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April 27, 2005
Consultant Team:
Michael Wallwork, P.E.
Sue Newberry
Alternate Street Design, P.A.
1516 Plainfield Avenue
Orange Park, FL 32073-3925
Table of Contents
1.0 Introduction 3
1.1 How to Use the Handbook 4
2.0 Neighborhood Traffic Management Program Overview 5
2.1 Program Purpose 5
2.2 Traffic Management Areas 7
2.3 Techniques 7
2.4 Street Types 7
2.5 Sidewalks and Crossings 10
2.6 Bikeways 11
2.7 Street Network 12
2.8 Private Roads 12
2.9 Removal and Modification to existing treatments 13
3.0 Process
Project Development Process Chart 14
3.1 Neighborhood Traffic Management Request 15
3.2 Initial Neighborhood Traffic Meeting 15
3.3 Data Collection 16
3.4 Follow up Meeting 17
3.5 Preliminary Project Evaluation/Recommendation 18
3.6 Council Consideration 18
3.7 Assessment District 18
3.8 Neighborhood Workshop 19
3.9 Plan Evaluation/Review 19
3.10 Follow-up Neighborhood Workshop 19
3.11 Obtain Signatures 20
3.12 Approval/Funding 20
3.13 Final Design/Installation 20
3.14 Review 20
4.0 Toolbox 21
4.1 Traffic Control Devices 21
4.2 Education and Enforcement 22
4.3 Traffic Calming Treatments 25
Traffic Calming Treatment Selection Guide 28
5.0 Design Considerations 58
5.1 Project Development 58
5.2 Overall Design Review 59
5.3 Treatment Design 65
6.0 Traffic Calming Treatment Design Guidelines 73
Cross Reference 74
Treatment Layouts D-1 to D-25
Appendix 75
1.0 Introduction
Safe,pleasant residential streets that allow Encinitas residents to walk,bicycle, and socialize
have been a City priority for many years.Policies and practices to encourage neighborhood
traffic to proceed at appropriate speeds and through traffic to use major streets were implemented
in 1991. Some neighborhoods that have been affected by those policies are satisfied, but others
have concerns that have not yet been addressed. These concerns prompted development of a
more comprehensive program to provide options for addressing neighborhood traffic issues and
clearly define the implementation process. This handbook explains the Neighborhood Traffic
Management Program.
Citizen Involvement
Encinitas citizens have first-hand knowledge and experience of traffic patterns and concerns in
their neighborhoods. Every resident was invited to provide input to help identify key elements of
the neighborhood traffic program. Several hundred citizens attended workshops to contribute
their insights and suggestions during early stages of program development. Many more provided
comments via email and letters. This input helped shape a program that provides citizens with
information and tools to help them collaborate with the City to manage neighborhood traffic
efficiently and effectively.
Fp
x
Hundreds of Encinitas residents participated in two workshops to provide input for this program.
City of Encinitas Neighborhood Traffic Management Program
1.1 How to Use the Handbook
The handbook is divided into 6 sections.Sections 1.0 and 2.0 provide an overview of the
neighborhood traffic management program that will be useful for all readers.
Section 3.0 describes the process that is followed to initiate,design, and implement a neighbor-
hood traffic management plan. It includes a flow chart that visually illustrates the steps required
to complete the process. This section will be useful for all readers.
Section 4.0, Toolbox, explains different techniques that can be used alone or in combination with
other tools to manage neighborhood traffic. This section is vitally important to the program and
useful to all readers,but training to help residents understand this section will be incorporated
into the first two neighborhood meetings associated with initiating a Neighborhood Traffic Calm-
ing Plan process.Residents may find the summary in the chart on page 28 a useful tool for select-
ing which treatments they would like to study more closely.
Sections 5.0 and 6.0 are oriented to the designer who will assist residents with the development
of their neighborhood traffic management plan. These sections discuss many of the elements the
designer must consider before preparing preliminary plans.
City of Encinitas Neighborhood Traffic Management Program
2.0 Neighborhood Traffic Management:
Program Overview
Mission Statement:Develop and oversee a program that will encourage vehicles to use
circulation element streets;reduce impact of vehicular traffic in neighborhoods;and im-
prove pedestrian, bicyclist and equestrian safety within and around the City of Encinitas.
Adopted by the Traffic Commission, December, 2001
. P E substantial number of vehicles passing by their
LIMIT home every day.
i2o' 5 ' In some neighborhoods, the street pattern may
create short-cuts that attract drivers who are
trying to avoid congested areas. Their short-
s
cuts are referred to as cut-through routes. Some
Encinitas residents feel their neighborhoods are
experiencing cut-through traffic that has
created excessively high traffic volumes on
their streets.
In addition to concerns about traffic volume,
z many residents are concerned about traffic
speed. Most Encinitas residential streets are
2.1 Program Purpose posted for maximum speeds of 25 mph.
The purpose of managing neighborhood traffic Unfortunately, signs don't guarantee
flow and speed is to enhance safety and compliance. Many factors influence a driver's
preserve community character in Encinitas selection of travel speed. For example, the
neighborhoods. An expanded plan to manage width and length of a street affects the driver's
neighborhood traffic has become necessary for sense of what is an appropriate speed for the
those residential areas experiencing more environment. The number of people visible,
traffic and excessive speeds. amount of landscaping, weather conditions,
number of cars parked, and many other factors
Concerns about increasing traffic and speeds are quickly processed by the driver's mind to
are prevalent throughout the United States. select a speed. The driver's temperament, trip
Americans are driving more than ever.
Commute distances are longer and the number "Make street environments that are safe,
of trips they take are increasing.A typical efficient, and pleasant for all transporta-
single family detached home in the San Diego tion system users—pedestrians, bicy-
area generates 10 daily trips. Estate homes clists, automobiles, skateboarders, horse-
generate 12 trips per day. This means that back riders, transit, etc. It should create
even residents in areas with little traffic from integrated systems that fit into the envi-
outside their neighborhood may notice a ronment." Citizen Statement, March, 2003
City of Encinitas Neighborhood Traffic Management Program
1
purpose, and time schedule are other suggested that creating more pedestrian-
considerations. The result is that many drivers friendly areas could help reduce the number of
do not adhere to the posted speed limit. daily trips made to and from Encinitas
households.
Balance User Needs Bicyclists, skaters, and others using various
Citizens who provided input to help develop types of non-motorized wheeled devices also
this program emphasized balancing the needs share streets with motorized vehicles and
of all who share Encinitas streets. The sample pedestrians.Whether for play or for
statement in the box on the previous page transportation, these street uses are permitted
reflects the perspective of many citizens. They and will be considered during the process of
expressed their desire for living in areas that developing neighborhood traffic management
are friendly, neighborly, and have a sense of schemes.
community. They wanted safe, peaceful
neighborhoods and identified low traffic Traffic management must also address the
volume and low speeds as a major determinate needs of those inside motorized vehicles. This
of quality of life in Encinitas: program strives to provide convenient,
efficient routes of travel for motorized
Most California citizens also place a high value vehicles. It also addresses the needs of those
on quick and easy motorized access to streets who provide various neighborhood services,
that carry them to work, school,highways and including the occasional moving van, garbage
freeways,or other destinations. It is important service, and emergency service providers.
to recognize the need for adequate, moderate
speed collector streets to meet this need. Community Character
The Neighborhood Traffic Management Street design has a profound impact on the
Program seeks to reconcile the desire for quick appearance of neighborhoods and the
and efficient mobility and that for quiet, low- functioning of a community.Wide, sterile
speed streets by designing a street environment streets with limited landscaping encourage
that functions well for people inside vehicles as faster speeds and are less desirable places to
well as for those who are not inside a vehicle. live. Many of the tools in the traffic
management program have the potential to
The first step in this process is to design enhance community character with added
pedestrian-friendly neighborhood streets. In a
pedestrian-friendly environment,people feel landscaping,reduced asphalt area, or more
defined and orderly parking spaces. Many
safe walking, the environment is comfortable, residents value the character of rural-style
access to destinations is convenient;and they . streets that have no curbs or gutter,but without
understand where they are and how to get proper treatments these streets sometimes
where they want to go. Children and others encourage higher speeds.
who do not drive autos are less reliant on
others for their transportation in pedestrian-
friendly areas. Some workshop participants
City of Encinitas Neighborhood Traffic Management Program
2.2 Traffic Management 2.3 Techniques
Areas There are many techniques, or tools, available
for managing neighborhood traffic. These
Designing one street to slow or limit traffic include traditional.signs and markings,
can impact residents and traffic on parallel
streets or other streets in the vicinity.For this enforcement, education, and traffic calming
reason,the Encinitas program approaches treatments.A variety of tools are included in
traffic management from a neighborhood
this program to allow Encinitas residents and
staff many alternatives when developing a
perspective,rather than astreet-by-street traffic management plan.
program.
Traffic control devices include stop signs,
For purposes of this program,neighborhoods traffic.signals, speed limit and other signs, and
will be defined primarily by existing street markings. These traffic control devices
boundaries such as freeways, major roads, require enforcement to achieve driver
beaches, rivers, creeks, or railroad tracks. For
compliance. Education is often used to
example, one traffic management encourage voluntary compliance and
neighborhood near the ocean might be understanding of the devices.
bounded by N. Coast Highway 101,the
beach, and streets such as La Costa Avenue, Traffic calming treatments are changes in the
Leucadia Boulevard or Encinitas Blvd. street used to reduce the ability of drivers to
Another is bounded by I-5, N. Coast travel at high speeds and to limit access to
Highway 101 and the same cross streets certain streets. This is accomplished by using
mentioned previously. Traffic management one or more treatment alternatives to create a
areas east of I-5 are challenging to define street environment that either requires drivers
because development patterns vary and often to steer over or around a street feature, or to
include many cul-de-sac and curvilinear take an alternative route. Other elements such
streets. as painting stripes on the street, landscaping
and signing do not force a change in driver
The optimum neighborhood size for effective behavior,but they provide visual elements that
traffic management outreach,public
involvement, and construction is one square may prompt people to drive more slowly.
mile. In neighborhoods that exceed this size, The tools available to manage traffic in
collector streets or other features will be used neighborhoods are discussed in detail in
to sub-divide the neighborhood into smaller Section 4.0 beginning on page 21.
segments. Ideally, traffic management area
boundaries will define areas where neighbors
share a sense of place and will work
collaboratively to develop a traffic plan that 2.4 Street Types
enjoys broad neighborhood support. Tool selection will be influenced by the nature
of the neighborhood street and sidewalk
Neighborhood boundaries will be defined by system and by objectives established by
staff with input from citizens.
City of Encinitas Neighborhood Traffic Management Program
•
residents. Streets and sidewalks provide a
network of routes that allow access to
destinations via foot, bicycle, or motorized w ± 11+
vehicles. Some Encinitas streets are primary
routes to commerce,nearby freeways, and
work or activity centers. The Neighborhood
Traffic Management Program was developed
x,
to address neighborhood streets that primarily
serve residential areas. Many of the options for � � k
neighborhood streets are not appropriate for
larger, primary routes. Criteria and standards
� 4
for these larger routes are addressed in the Typical rural-style residential street in Encinitas.
City's Circulation Element.
Rural-style Streets Some people feel the lack of curbs, gutters,
and sidewalks creates a rural environment
There are many two lane undivided rural-style that would be lost if curbs and gutters were
streets in neighborhoods throughout Encinitas. installed. It is harder to manage traffic on
These paved streets are generally about 24 feet streets that do not have curbs and gutters
wide and do not have curbs, gutters, or because drivers can maneuver around many
sidewalks. As shown in the photo of a typical traffic calming measures. It is possible to
rural-style residential street, people walking in install steel posts or other solid objects to
these areas are forced into the vehicle travel prevent this action, but these objects are often
lanes. Many rural-style streets are winding, ugly.
hilly streets that limit the ability of drivers to
see people, animals, parked cars, or other Another option is to install curbs and gutters
objects within adequate braking distance. In that define a narrow street. As shown in some
some areas vegetation at street edges limit of the images on pages 10 and 11, streets
driver visibility. Rural-style streets send a with curbs, gutters, and sidewalks can have a
message to drivers that the area is rural and it natural feel if they are narrow and well-
is appropriate to drive fast. landscaped. These streets provide a better
balance between user needs than rural-style
Cars parked on unimproved shoulders in front streets that do not have curbs.
of homes line both sides of some Encinitas
streets. Drivers often park several feet further
from the street edge than they would on a street Suburban-style Streets
with curbs. In effect,this widens the usable Suburban-style streets are paved and have
roadway and allows faster speeds, especially curb and gutter. Suburban streets usually
around corners. Drivers are able to maintain include sidewalks. Many have planter strips
higher speeds around corners because they can between the travel lane and sidewalk. They
drive on the shoulder. provide the safest and most comfortable
City of Encinitas Neighborhood Traffic Management Program
1
environment for all users when they are only
24 feet wide, with on-street parking
encouraged. As shown in the photo on the
right, some existing suburban-style streets in
Encinitas do not have sidewalks. Parents are -
reluctant to let their children walk in the street
because they are exposed to passing vehicles. k
To optimize safety, new streets and streets that
are reconstructed should include sidewalks or
other pedestrian paths and planter strips on
both sides where feasible. See Section 2.5, _ =
Sidewalks and Crossing for additional ;
information.
Suburban streets in Encinitas include some with
Street Classifications Sidewalks, as shown below, and some with curbs
and gutters, but no sidewalks, as shown above.
Both rural and suburban-style streets in
Encinitas are classified by their function. .
Classifications include local, collector and
arterial streets. These classifications are a
consideration when selecting traffic calming
measures or traffic control devices most
appropriate for the street.
Local Streets
Local streets primarily serve as access to
residences. Existing local, or residential, streets
in Encinitas vary in paved width from 18 to 50 Local streets such as the one above primary pro-
feet. vide access to residences.
Collector Streets
Collector streets provide connections between
arterial streets and local streets. The Encinitas
Circulation Element designates which streets
are collector streets based upon the need to
provide a network that allows motorists to
access arterials and freeways. Development
patterns play a major role in determining which
streets are designated as collector streets. In Example narrow local street with sidewalks,
neighborhoods with many connecting streets, planter strips, and on-street parking.
City of Encinitas Neighborhood Traffic Management Program
traffic tends to be distributed evenly on each
street throughout the street system.
Neighborhoods with cul-de-sacs and loop
streets concentrate traffic onto a few collector
streets.Wide collector streets can create a
barrier to pedestrian and bicycle movements
across a neighborhood. Vehicle speeds area
generally higher on wide streets. �
Arterial Streets
Arterial streets provide long distance travel
routes across and between cities. They are Typical two-lane collector street in Encinitas.
usually 4 to 6 lanes wide and often include
medians,planter strips, and sidewalks. Arterial
streets are designed to handle more traffic than N_'
is normally expected on local and collector
streets.
2.5 Sidewalks and Crossings
One of the objectives of neighborhood traffic
management is to create more pedestrian-
friendly neighborhoods. Sidewalks and defined
pathways are essential features of a safe Typical three-lane collector street in Encinitas.
walking environment. Walking in the street
because there are no sidewalks may feel safe ,
and comfortable to a normal,healthy adult if K s
traffic volume and speed is low,but it presents
a hazard to children,people in wheelchairs, ti„
those with visual or hearing impairments, and
those who may be slower to see and react to
the presence of a vehicle. Crash data from
across the U.S. clearly indicates there is a
d
higher probability of injury when walking in t .
z>
areas with no sidewalks. These are random
events that happen seldom,but can have tragic
outcomes. For Encinitas to become pedestrian- The City of Encinitas allows sidewalk and path-
way materials such as decomposed granite to
friendly, sidewalks or defined pedestrian paths complement the character of a neighborhood.
are needed on both sides of streets where Applicable standards must be followed.
City of Encinitas Neighborhood Traffic Management Program
children play or walk to school and where
friends and neighbors walk and socialize. ;
Sidewalks can be attached to the curb, as
shown in the image on the right, or separated r:
from traffic with a planter strip, as shown in
the lower photo. The planter strips provides
space for landscaping and separates walkers t _
from moving traffic. Natural or decomposed
granite walkways are also appropriate in some
areas.
The Encinitas Recreational Trails Master Plan Typical suburban local or collector street with
contains a map of a citywide trail system and sidewalks attached to the curb. This street is 40'
guidelines for materials and trail locations. wide from curb-to-curb.
Hard and soft surface paths are identified in the
plan, as well as sidewalk connections within
the trail system. Traffic management plans
must be compliant with the Plan and City
sidewalk standards.
Ease in crossing the street is also a key factor
in designing a pedestrian and bicycle-friendly
environment. The Traffic Calming Treatments
section of the Toolbox includes features that
can be used to minimize the length of time a
pedestrian is in the street. Short crossing
distances and slower vehicle speeds contribute
to the comfort and security of people crossing Narrow, suburban local or collector street with
the street. sidewalks separated from traffic by a planter strip.
2.6 Bikeways Bike Paths (Multi-Use Trails)
Bicyclists also share Encinitas streets. Their Paths and trails that are separated from streets
needs and concerns are important and must be
considered during the development of can provide a quiet, comfortable bicycling
and walking environment. Multi-use trails add
neighborhood traffic plans. Two types of
bikeway facilities that should be considered value to adjacent properties and can often
when preparing Neighborhood Traffic provide short-cuts that link together areas that
Management plans are described below. The are less accessible to motorized vehicles.
City's Master Bikeway Plan should also be Trails are problematic when they parallel
streets in areas with many driveways and
consulted. cross streets because there is a potential
City of Encinitas Neighborhood Traffic Management Program
conflict at each driveway and intersection. For they are typified by single connections to aerial
this reason,multi-use trails are best when roads,they generate much higher traffic
located in corridors away from streets. On- volume on arterial roads and greatly increase
street bicycle facilities may be more practical turning movement at major intersections.
when routes are adjacent to a street.
These types of developments also generate a
higher number of internal trips because of
Bike Lanes limited mobility for pedestrians and bicyclist
Bike lanes are designated areas in the street within the development.
adjacent to the vehicle travel lane. They are
included as a tool in the traffic calming Because of people's fears and lack of
treatments because adding bike lanes to knowledge of how to calm traffic,
existing streets will help reduce lane widths, interconnections between neighborhoods are
which contributes to slower speeds. Bike lanes fought and often prevented. The results are
in neighborhoods are most applicable on longer travel distances affecting more people
collector and residential streets carrying more within their neighborhood, lowered emergency
than 1,500 vehicles per day. response times and higher service costs.
Therefore,to minimize emergency response
times, service costs and the number and length
2.7 Street Network of trips a well-interconnected street system is
Street networks can have enormous impacts on the long-term goal.
traffic volumes in residential streets.
Identification and construction of the"missing
An interconnected street network either the links"within the existing street network as
historic grid network or an interconnected traffic calmed link is another goal to reduce
network of curved roads produce the lowest emergency response times,trip lengths and the
traffic volumes on any one street and on the number of trips.
arterial road network. These street networks
minimize service costs,provide the highest 2.8 Private Roads
level of accessibility to emergency vehicles, Many private roads have been constructed and
and produce the lowest number of internal trips more are likely to be constructed. If residents
because so many trips can be done be walking on these streets wish to implement traffic
or bicycling. calming,they are encouraged to follow an
Cul-de-sac style development with single abbreviated version of the process described in
entrances produce very light traffic volumes on this Manual and their Covenant, Conditions
the tops of cul-de-sac and very high volumes and Restrictions. Funding will be at the cost of
where the cul-de-sac development connects to the Homeowners Association with the review
the arterial road. Therefore,there is a huge
and approval of the City.
disparity of traffic volumes for people living
within this style of development. Because
City of Encinitas Neighborhood Traffic Management Program
2.9 Removal and Modifica-
tion to existing treatments
Over time the traffic pattern changes, the range
of treatments widens,the mix of residents
along a street changes and therefore a review
of past traffic management projects become
desirable. A review may be initiated by the
residents, or the City. A review would con-
sider the initial conditions, changes,reasons
for the change, and a review to see if the
change is warranted.
If warranted, a public workshop of the affected
residents is held to consider the change,the
data and if there is consensus, the change could
be implemented and funded by the initialing
body.
City of Encinitas Neighborhood Traffic Management Program
Figure 1 Project Development Process
el 11
Citizen, staff, Traffic Com- Traffic Engineering reviews Neighborhood Traffic Coali-
mission, or city Council request; schedules&con- tion (NTC)formed. Do they
submit Neighborhood Traf- -� ducts initial neighborhood wish to proceed?
fic Management Request traffic meeting
YES NO
Lion summarizing data [Data collected &analyzed
s with recommenda-
mitted to November I
Commission meeting NTC Meeting/Does data
meet minimum?
Follow up with NTC if
Yes No
objectives not met.
I LEI No
Council considers •
whether to proceed with Voluntary Education Collect post-project
project design/funding Campaign and/or data
non-structural measures
Yes
No Final design, permit-
ting. Council ap-
City funding available proval, installation
within 3 years
City funding Waiting list
not available
within 3 years Neighborhood Work-
shop conducted; con- Yes No
ceptual plan developed t
67%of neighbors Create self
Create self support plan? assessment
assessment Yes
Evaluate plan; reviews district?
district. ,. ..
as needed
I L�e s No Funded?t � No
No Yes w
Neighborhood Work- Traffic Commission Yes No
On waiting shop;concept plan supports plan?
reviewed/revised
list until fund- 11 City Council approves
ing available. No Yes conceptual plan?
Redesign
City of Encinitas Neighborhood Traffic Management Program
Neighborhood Trajc Coalition(NTC), and
3.0 Process serve as the liaison between City staff and
other residents. One resident or the party
This section describes the process to develop filing the request must commit to host an
and implement a neighborhood traffic initial meeting of 1-1/2 to 2 hours. If a plan is
management plan. The chart on page 14 prepared, this group will be a key resource in
illustrates the steps in the overall process.Each explaining details to neighbors who did not
step is described in detail below. attend meetings and in gaining their support
3.1 Neighborhood Traffic for the project.
Management Request 3.2 Initial Neighborhood
The process to develop a traffic management Traffic Meeting
plan for any neighborhood can be initiated by After reviewing the Neighborhood Traffic
residents, staff, City Council, or by a vote of Management Request and affected area, City
the Traffic Commission. staff will contact the Host to schedule the
initial meeting. This process may take up to
A Neighborhood Traffic Management Request 90 days.
must be completed, signed by ten residents,
and filed with the Engineering Department. The Host is to invite the ten signatories and
The request provides preliminary information other interested people to the initial meeting.
regarding the nature and location of the traffic The agenda will include:
concern. This will provide staff with
information needed to conduct a field review to Host: Welcome,Introductions, and Overview
prepare for the preliminary neighborhood of Concerns
meeting.
Staff: Traffic Management Presentation
A request can be filed at any time,but it must explaining the program purpose,proposed
be received by October 1 to be considered for neighborhood boundaries, procedures,
inclusion on the ranked list that will be funding options, and possible outcomes. Staff
developed and submitted to the Traffic will explain when and how enforcement,
Commission during November of each year. signs, or other preliminary steps are feasible.
Staff will respond to questions and work with
Residents from ten different households on at residents to explore their options.
least four streets in the neighborhood must
agree to attend an initial meeting to learn more If the residents who attend the meeting
about neighborhood traffic management and represent at least 4 streets within the
how it can be implemented. This core group neighborhood and they agree to take on the
should be willing to assist the City in efforts to role of the NTC supporting development of a
encourage all residents in the neighborhood to neighborhood traffic plan, staff will schedule
participate if a traffic management plan is data collection for the area.
developed. They will be referred to as the
City of Encinitas Neighborhood Traffic Management Program
1
3.3 Data Collection times are evaluated to see if that vehicle
entered and left the neighborhood within
Data is collected to determine the magnitude of the normal travel time plus 2 minutes. The
the traffic concerns in comparison to other goal is to separate through traffic from
neighborhoods requesting traffic management. traffic entering a neighborhood to pickup
Some data elements will be used to rank or drop off people or goods.
project priorities. If a project is implemented,
data can be compared to conditions after 5. Crash information. Crash records from the
implementation to measure success. Data Sheriff's Office will be used to determine
collection will vary based on input provided by the number and type of crashes that have
citizens during the preliminary neighborhood occurred with the neighborhood within the
meeting. Data elements could include: last three years.
1. Speed. Speeds are recorded to quantify 6. Pedestrian Generators. Schools,parks,
how many drivers exceed the speed limit. community centers,public facilities, or
Engineers use the term, 85th percentile, to other destinations that attract pedestrians
describe the speed at or below which 85 will be counted to provide information for
percent of the motorists on a street travel as data in Figure 2 on the following page.
they pass the measuring device.
7. Pedestrian counts. The number of
2. Cut-Through Volume. The number of pedestrians at a selected site(s) during a
vehicles that enter a neighborhood,travel specific period of time may be counted to
through, and leave without accessing verify pedestrian destinations.
neighborhood sites.
8. Pedestrian surveys. Observational surveys
3. Truck volumes. A truck volume count may can identify where pedestrian crossings are
be conducted to determine if trucks are needed and where potential conflicts exist.
cutting through a neighborhood. These may be particularly appropriate for
areas near schools, playgrounds, sports
4. Origination and destination surveys. These complexes, or other activity areas.
surveys collect data to determine the
number of vehicles that are cutting through 9. Sidewalks and pathways. Streets within the
a neighborhood. To collect this neighborhood will be assessed to determine
information, a person is stationed at the where sidewalks or pathways are in place
neighborhood entry point and another is to provide information for data in Figure 2
stationed at the neighborhood exit point. on the following page.
The type, color,license number, direction
of entry and time of day each vehicle enters r 0 .Bicyclist counts. The number of bicyclists
the neighborhood is recorded. The person at a selected site(s)during a specific period
at the exit point notes the same information of time may be counted.
for each exiting vehicle. This information
Data collected will be compiled by City staff.
is compiled and compared. When two
vehicle details match, the entry and exit
City of Encinitas Neighborhood Traffic Management Program
Figure 2. Data Element Values
Data Element Points Basis for Points
Speed 0 to 30 Extent that 85th percentile* speeds exceed speed limit;2 points
assigned for every 1 mph over speed limit
Cut-Through 0 to 25 1 point for every 5 vehicles that cut-through the neighborhood during .
Volume the AM or PM peak hour on an average day
Crashes 0 to 15 1 point for every nonfatal crash and 5 points for every fatal crash re-
corded by the Sheriff's Department in the last 3 years
Pedestrian 0 to 20 5 points for every school,park,community center,library,or other
Generators public facility within the impact area
5 points if there are not continuous sidewalks or pathways on one side
Sidewalks or 0 to 10 of all local residential streets or both sides of all collectors;10 points
pathways
if there are no sidewalks
Total Points
Possible 100
*The 85th percentile speed is the speed at or below which 85 percent of the vehicles travel.
Figure 2 above shows how a value is assigned Figure 3. Other Factors in Project Selection
to each data element. When data such as speed . Scheduled street or utility work
and volume is gathered at more than one • Other construction projects
location within a neighborhood, points will be • Other engineering considerations
assigned for each location and then averaged to • Fire Department priorities
ensure equitable comparisons. • Sheriff s Department priorities
• Consistency with the General Plan
• Consistency with the Bikeway Master
3.4 Follow up Meeting Plan
• Consistency with the Recreational Trails
The NTC will host a follow up meeting at Plan
which data gathered will be presented by staff. • Consistency with other adopted City
a
A total score of 51 points is required for the plans
neighborhood to qualify for traffic calming
treatments. All neighborhoods qualify for
resident-based educational campaigns and signs The City Engineer will forward all
or other nonstructural traffic safety upgrades. Neighborhood Traffic Management Requests,
Education campaigns will be supplemented by compiled data, meeting results, and a staff
enforcement as resources permit. See section recommendation to the Traffic Commission,
4.2 for additional information. with copies to the Neighborhood Traffic
City of Encinitas Neighborhood Traffic Management Program
•
Coalition contact member. The Traffic
Commission will review staff
recommendations and provide a ranked listed
of projects to City Council for approval.
3.5 Preliminary Projects 1�
Evaluation/Recommendation
There are many neighborhoods in Encinitas
that may want to participate in the
Neighborhood Traffic Management Program.
A ranked list of the neighborhood by total A neighborhood workshop will provide an opportu-
number of averaged points received will be nity for citizens to identify problems, establish ob-
jectives, learn about potential solutions, and work
prepared. together to create a conceptual traffic plan.
Figure 3 on the previous page lists factors that
will influence the priority assigned to each
Neighborhood Workshop as described in 3.8.
neighborhood in addition to the data score.
Citizens in neighborhoods that are not funded
These factors must be evaluated by staff to
ensure that resources are expended efficiently.
within three years may elect to establish an
assessment district as described in 3.7.
For example, if a project is ranked first,but the
street is scheduled for reconstruction soon, it is 3.7 Assessment District
more cost effective and efficient to delay the
project to coincide with other construction. If a project does not score 51 points or is
Other situations such as development plans or ranked lower than other projects included in
the City funded work plan, funding and
public safety may influence priorities. Staff
will prepare a recommendation that includes a construction will be unavailable within 3 years.
full explanation of all factors considered for The Neighborhood Traffic Coalition may poll
the November meeting of the Traffic residents to determine if they are willing to
Commission. create aself-assessment district. If 67% of
property owners within the neighborhood sign
3.6 Council Consideration a covenant agreeing not to oppose an
assessment district, the Neighborhood Traffic
The City Council will consider the Traffic
Coalition may request that the project be
Commission recommendation at their annual included in the Neighborhood Traffic
goal-setting meeting in January. Based on
direction from this meeting, staff will present Management work plan.
formal reports,project priorities, and Staff will provide a range of likely project
recommendations with funding options to the costs for use in determining if an assessment
Council in late February or March. Approved district covenant is an acceptable alternative.
projects for which funding is available within Final costs are dependent upon the plan
three years will be scheduled for a developed.
City of Encinitas Neighborhood Traffic Management Program
1
The self-assessment district will be formed 3.9 Plan Evaluation/Review
after residents develop and approve their traffic The conceptual plan developed during the first
management plan. The self-assessment district neighborhood workshop reflects the advice and
will distribute project design and wishes of the neighborhood. Their concepts
implementation costs fairly among all residents must undergo an engineering evaluation to
within neighborhood boundaries.Refer to the refine the ideas, ensure that the measures
City's Assessment District Policy for proposed by the community are appropriate for
additional information. the locations selected and objectives defined,
and regulatory requirements can be met. The
Another alternative is for the neighborhood to Sheriff's Department,Fire Department, and
post a cash deposit to cover estimated expenses other City or regulatory entities will be
associated with conceptual plan development. included in the plan review as required. When
necessary, staff may recommend a different
treatment or placement.
3.8 Neighborhood Workshop
The Neighborhood Traffic Coalition for each It is the policy of the City to require traffic
area included in the annual Neighborhood management treatments to be aesthetically
Traffic Management Program work will be pleasing and consistent with the character of
contacted to help coordinate a neighborhood the community for which they are designed.
workshop after funding has been identified and The Department will not recommend approval
at other points during the process.Workshops of plans which fail to meet this criteria.
will be open to all residents who could be
impacted by the traffic management plan. 3.10 Follow-Up
Coalition members will play a key role in Neighborhood Workshop
encouraging their neighbors to participate. After the review a preliminary layout will be
Sheriff's and Fire Departments will be part of prepared and presented at a follow-up
the process to provide input about problems, neighborhood workshop. Once again the
such as crashes, enforcement, and emergency Neighborhood Traffic Coalition will be called
vehicle routes. upon to encourage neighbors to attend the
The first of these workshops will provide an workshop and provide feedback on the
opportunity for residents to identify concerns, preliminary layout. The preliminary layout
establish objectives, learn about potential may include one or more alternatives. The goal
solutions, and develop a conceptual plan with of this meeting is to achieve consensus that the
the guidance of a trained professional. This layout is acceptable to the neighborhood.
meeting allows neighbors to discuss their Reaching agreement could require
individual preferences, explore consequences, compromises or changes in the preliminary
settle any differences of opinion, and reach layout. If agreement cannot be reached during
consensus. the meeting, a follow-up meeting will be
scheduled where revised layouts will be
City of Encinitas Neighborhood Traffic Management Program
presented. After this meeting a cost estimate projects not approved for any other reasons
will be prepared. will be handled on a case-by-case basis.
3.11 Obtain Signatures 3.13 Final Design/
The Neighborhood Traffic Coalition is Installation
charged with the responsibility of obtaining
the written support of 67% of the property Construction plans will be developed after
owners within the neighborhood boundary for projects are approved and funded. In some
the proposed plan and for a covenant not to cases, the plans may call for phased
oppose a Lighting and Landscaping Sub implementation,with early strategies that do
District(LLD)to maintain the facilities once not require construction.
they are constructed. The Neighborhood Traffic Coalition will
assist in the review of construction plans and
3.12 Approval/Funding in development of landscaping plans.
After the signatures have been gathered and Throughout this process, this group may be
verified,the preliminary plan will be called upon to participate in discussions with
presented for final approval and funding.The impacted residents,provide input on design
approval process includes: issues, and serve as liaison with the
1. The Traffic Commission considers the neighborhood.
plan. If they approve it, the plan moves to 3,14 Review
the Council. If they do not approve the
plan, staff will schedule an additional An essential step in any program is to
workshop for the neighborhood to revise measure the success. Following
the plan.When a plan is approved by the implementation of a neighborhood traffic
Traffic Commission,it will be presented management plan,periodic data collection
to the City Council for final approval and will be conducted. This data will be
funding compared to pre-project data to determine the
effectiveness of the implemented plan. If the
2. The City Council may approve the plan or data indicates that the objectives defined by
request the neighborhood revise the plan. the neighborhood are not being met, a
If the plan is approved but not funded the follow-up meeting will be conducted with the
neighborhood again has the option of Neighborhood Traffic Coalition. The
creating a self-assessment district as outcome of this meeting will determine the
described in 3.7. If they choose not to next steps.
select this alternative, the project may be
cancelled or moved to the waiting list.
In the event revisions are requested by either
entity, staff will collaborate with the NTC to
achieve a plan acceptable to all parties.
City of Encinitas Neighborhood Traffic Management Program
4.0 Toolbox the document defining Federal requirements
for traffic control devices, states that stop signs
Techniques for managing traffic range from should not be used for speed control. It further
passive approaches, such as education,to states that they should be installed in a manner
reconstruction of streets. This section contains that minimizes the number of vehicles that
a"toolbox" filled with potential solutions for must stop.When a stop sign is used, MUTCD
neighborhood traffic concerns. specifies that it should be installed on the street
carrying the lowest volume of traffic. Multi-
4.1 Traffic Control Devices way Stops, in which traffic from all directions
must stop, can be installed as mitigation for
Stop signs, traffic signs, and traffic signals play crashes onto manage vehicular,pedestrian and
a role in the management of neighborhood bicycle traffic that has reached minimum
traffic that differs from the role of traffic volumes specified by regulating agencies.
calming measures. Traffic calming treatments
are designed to slow vehicle speeds or divert Intersection traffic calming treatments are
cut-through traffic. Stop signs, traffic signs, more effective than stop signs in controlling
and signals manage pedestrian,bicycle, and speeds, reducing intersection conflicts, and
motorized vehicle traffic at a variety of speeds maintaining a smooth flow of traffic. Residents
in diverse conditions. These devices, along who provided input during the development of
with pavement markings, are regulated by. the program envisioned replacing many
Caltrans and by the Federal Department of existing neighborhood stop signs with small
Transportation to ensure uniformity throughout roundabouts or traffic calming circles. There
the United States.The regulations have may be instances where stop signs are needed
evolved since the 1930's as a method to either as a temporary control until a traffic
provide uniform information to all users of the calming treatment can be installed, or as a
roadway. permanent installation. Residents will be
encouraged to explore all other possible
Residents often request installation of various solutions before providing their
signs to address speeding and cut-through recommendation.
concerns in their neighborhoods. The
conditions under which these signs are used are
d Traffic Signals
discussed below.
Traffic signals are used at intersections that
Stop Signs meet conditions established in the MUTCD.
Their purpose is to assign right-of-way and
Stop signs are used at unsignalized provide for the orderly movement of traffic.
intersections where right-of-way must be They are sometimes used to interrupt heavy
regulated because of speeds, crash problems, traffic at intervals to permit other traffic,
or restricted driver views. The Manual on vehicular or pedestrian,to cross. Poorly
Uniform Traffic Control Devices (MUTCD), conceived or unjustified traffic signals can
City of Encinitas Neighborhood Traffic Management Program
create excessive delay, contribute to red light there is a possibility of being cited. Signs that
running or other violations, cause diversion of prohibit or limit other actions such as
traffic onto less adequate routes that have pedestrian crossings,turning movements, and
fewer stops, increase liability, and increase the parking may also be disregarded unless
frequency of collisions. accompanied by a change in street design or
enforcement. Signs such as Children at Play
Traffic signals can also help to create acut- and Deaf Child do not tell a driver what to
through route through several neighborhoods do.Where they have been used, they usually
by providing easy access into and out of fail to affect driver behavior.
neighborhoods. Installation of traffic signals at
several intersections along a collector street The MUTCD recommends conservative use
can turn that street into a major thoroughfare. of regulatory and warning signs because
The added traffic impacts residents on the signs tend lose their effectiveness if used to
collector street. The installation of signals excess. Overuse of signs also leads to sign
needs to be carefully regulated to avoid clutter that is aesthetically unappealing.
unintended adverse consequences.
Temporary signs used to conduct campaigns
Conservative,well-planned use of signals to to reduce speeds or raise awareness are
complement other components of a discussed in the following section.
neighborhood traffic calming plan will be
considered during the development of traffic
management plans for Encinitas
neighborhoods. However, in most cases traffic 4.2 Education and
calming treatments are preferred for Enforcement
controlling intersection movements because of
their safety, speed reduction, traffic flow, and The education component of the
capacity benefits. Neighborhood Traffic Management Program
features brochures and website information
that explain the program,why it is needed,
Other Signs and the steps citizens can take to implement
There are many other regulatory signs that the program in their neighborhood. Residents
meet national standards and are used to provide play a key role in distributing information
information and manage traffic. Speed limit about the program and in helping their
signs display the maximum speed allowed neighbors understand their role in developing
under local ordinances. Unfortunately, most and implementing a neighborhood plan.
motorists disregard signs, especially on wide,
straight streets where they feel comfortable and Education Campaigns
in control of their vehicle at higher speeds.
Flashing beacons are sometimes added to Posted speed limits are the most common
speed limit signs in school zones, but even form of education aimed at slowing drivers.
these may be disregarded unless motorists feel Unfortunately, experience has demonstrated
City of Encinitas Neighborhood Traffic Management Program
that just posting the maximum legal speed
does not compel every driver to proceed at
that speed. If speed limit signs were
SPA
completely effective, there would be no need UNIT
for a traffic calming treatment program.
There are other education approaches
designed to encourage drivers to travel at . 0;
slower speeds. These include printed
brochures,radio or television
announcements,radar speed trailers (to show
drivers their speed as they pass), and Speed trailers use radar to detect motorist speed.
programs in which drivers pledge to drive at The actual speed is displayed beneath the posted
speed limit sign. They are most effective in slow-
or below speed limits to "pace"other traffic. ing drivers when used in conjunction with spo-
Some advocates suggest block parties and radic enforcement, but drivers often return to
front-yard activities to slow traffic. Several previous speeds soon after the sign is moved. The
commercial enterprises offer non-regulatory photo below shows other signs that are used in
Encinitas to encourage drivers to slow down.
signs with slogans that encourage motorists
to slow down. An example is the"Keep Kids
J.u !;
Alive" sign pictured on the right. No data is
available to demonstrate the effectiveness of
the these efforts. Citizens in some
communities use radar guns to record speeds "
and report offenders to enforcement agencies. M
25
Many of these methods are resource-
dependent.
Resident Role
As discussed in Section 2, the character and -
design of streets impact driving speed. take the lead role in organizing a campaign.
Drivers, especially those most familiar with
the area, may not notice how fast they are The first step is for concerned residents to
driving. In neighborhoods where most of the voluntarily commit to driving at posted speed
traffic is generated by local destinations, an limits themselves. Not only does this practice
educational campaign administered by set a good example, it forces drivers behind
residents has the potential to raise driver this vehicle to also obey the speed limit.
awareness and result in fewer vehicles
An additional step is for concerned residents
exceeding posted speed limits. This type of
education campaign is simple and direct. The to distribute copies of the City of Encinitas
Neighborhood Traffic Coalition (NTC)could brochure, What is Traffic Calming. The City
will provide brochures to the Neighborhood
City of Encinitas Neighborhood Traffic Management Program
Traffic Coalition. They may choose to accompanied by focused education
distribute brochures to all residents, or they campaigns can boost the effectiveness of
may prefer to target households where traditional enforcement methods. These
offending drivers reside, visit,or provide campaigns often share information about
services. when and where enforcement will be
conducted. This approach encourages many
Although no empirical evidence exists to drivers to change their driving habits in that
demonstrate long-lasting results from this type area, freeing officers to ticket the few who
of educational approach, it is reasonable to didn't heed the message. This stepped-up
expect an improvement, at least temporarily, enforcement program may be repeated at
If residents continue their educational efforts, random intervals in the same area until
it may be feasible to sustain educational drivers change their patterns.
program impacts.
The NTC can conduct a neighborhood-
Enforcement version of combined education and
enforcement program by distributing
Even the most successful education campaign brochures and sharing information that
cannot be expected to change the practices of stepped-up enforcement is expected over the
every driver,just as installation of a stop sign coming weeks. The purpose of advising
does not guarantee compliance by every drivers to expect enforcement is to raise their
driver. Enforcement is necessary. Traffic awareness of driving speeds.
calming treatments reduce the need for
enforcement by compelling the majority of
motorists to slow down to maneuver through Summary
geometric changes in the roadway. But even Voluntary education campaigns offer
with treatments in place enforcement may still residents an option that can be useful while
be needed for the occasional driver whose waiting for development and implementation
behavior is still unacceptable for conditions. of a traffic management plan. They also
Enforcement resources are limited, although provide an alternative for neighborhoods that
the Sheriff's Department will continue to be do not qualify for traffic calming treatments.
responsive to resident concerns to the extend In this case, it may be just a few drivers who
possible. Combining enforcement with a are causing the problem and an educational
resident-based education program can help program may complete resolve the problem.
maximize these limited resources.
Combined Education and Enforcement
Research conducted by the National Highway
Traffic Safety Administration shows that
enforcement that targets specific areas and is
City of Encinitas Neighborhood Traffic Management Program
4.3 Traffic Calming Treatments
The Traffic Calming Treatments portion of classification, width,number of vehicles, and if
the Toolbox describes physical changes to the the treatment is appropriate on bus or
street environment that are intended to reduce emergency service (EMS)routes. Street
negative effects of motor vehicle use, alter classifications are explained in detail on page
driver behavior and improve bicycling and 10. The Selection Guide and the following
walking conditions. Each change is pages are provided to help citizens evaluate
considered a traffic calming treatment. which traffic calming treatments will meet their
objectives as they help develop their
Most treatments achieve results by requiring Neighborhood Traffic Management Plan.
drivers to go over or around a permanent
feature placed in their travel path. This forced Unless otherwise noted, all treatments can be
maneuver is referred to as deflection. Vertical expected to reduce vehicle speeds. Their exact
deflection requires a driver to go over some- impact on speeds will vary based on the
thing and horizontal deflection requires treatment, its design, street characteristics,
drivers to go around something. Some number of vehicles parked on the street,
treatments create diversions that force drivers landscaping and other visual elements within
to alter their route. Some treatments rely upon the driver's view, and the number of vehicles,
changing the driver's perception of the street. bicyclists, and pedestrians using the street.
For example, visually narrowing the street
with striping may change the perceived width Many traffic calming treatments can be
of the street,prompting drivers to drive more designed to include landscaping space, which
slowly. adds visual appeal to the street and improves
the visibility of the treatment. The additional
Beginning on page 29, each traffic calming cost and maintenance of landscaping could be
treatment is described and illustrated. perceived:as a disadvantage by some. The
Appropriate locations, advantages, advantages and disadvantages of landscaping
disadvantages and cost ranges are provided. are discussed in more detail beginning on page
Selection of the tools to calm a neighborhood 63,but are not listed individually under each
requires careful evaluation of the impact the treatment. Traffic calming treatments are
treatment will have on residents, those divided into the following categories:
providing services to residents, visitors,
emergency vehicles,bicyclists,pedestrians, • Intersection: Treatments installed where
and those who are cutting-through the 2 or more streets intersect.
neighborhood. • Non-intersection:-Treatments installed
between intersections.
The Traffic Calming Treatment Selection
• Other: Use of curbs, parking or stripes
Guide on page 26 provides guidance for to reduce the actual or perceived street
selecting treatments best suited to the street width
City of Encinitas Neighborhood Traffic Management Program
1
Intersection Treatments Non-intersection Treatments
Intersections are the highest conflict areas in The traffic calming treatments in this section
the street network,making them a logical are used between intersections,usually at
location to slow traffic.Traffic calming intervals of 400-800 feet. They may be placed
treatments installed at intersections impact all in addition to intersection treatments. Careful
streets forming the intersection and often selection of the treatment and its location is
provide a visual break in a long stretch of needed to minimize inconvenience to adjacent
asphalt that contributes to fast speeds. properties.
Intersection treatments can improve safety by
eliminating unsafe movements, slowing
Other Treatments
turning and through speeds,improving driver
visibility, and shortening pedestrian crossing Several treatments to streets that do not create
distances. Vehicles parked close to or at an horizontal or vertical deflection can have
intersection often restrict driver visibility of some impact on vehicle speeds. These
approaching vehicles. Many intersection methods all involve changing the actual or
treatments overcome this by physically perceived width of the street.Like other
preventing parking. Treatments often increase treatments,their impact will vary based on
sidewalk space and enhance visual appeal with street characteristics and use. In general,
added landscape area. treatments in this category will not produce
behavioral changes comparable to those
The needs of large vehicles, including fire achieved by diverting traffic or requiring
trucks, moving vans, transit, school buses, drivers to maneuver over or around a traffic
garbage and deliver trucks must be considered calming treatment.
when intersection treatments are selected. For
example, a treatment that slows right turning Treatment Costs
vehicles will also slow the right turns of
emergency medical service (EMS)routes. Preliminary cost ranges are provided for
many treatments in the program. The number
Four intersection treatments are grouped as a of treatments per project,drainage, street
subcategory entitled Diverters. Diverters characteristics, and many other factors
restrict entry and/or exit routes and create influence cost. The estimates were calculated
circuitous routes for residents and emergency for a standard design on a typical street,then
providers, which increases volumes on other varied plus or minus 20 percent. These
streets. Neighbors working together to select estimates provide some budgeting guidance
treatments must consider how a diverter will for planning purposes. More precise costs can
impact traffic flow on other streets, as well as be calculated after the neighborhood plan is
their own travel routes. Diverters of any type developed.
are less desirable than other intersection
treatments and should be used sparingly, if at Treatment Selection
all. Cut-through traffic can be discouraged
with other treatments that are less restrictive. The traffic calming treatments on the
City of Encinitas Neighborhood Traffic Management Program
following pages were selected for inclusion
in the program based on input from citizens
during workshops.
Some guidance is provided for use in
evaluating treatments,but there is no formula
for selecting the perfect treatment or
combination of treatments. Residents must
study their options, discuss the advantages
and disadvantages of various treatments, and
work with staff and each other to select
treatments that best meet neighborhood and
citywide traffic management objectives.
City of Encinitas Neighborhood Traffic Management Program
Traffic Calming Treatment Selection Guide
Measure Street Width and Classification Other Considerations Page
® D EMS/
ry o 0 o - Maximum Daily Bus
(D �, a 0 Traffic Volume Route
a� o
INTERSECTION
Roundabout • • • • 29
Traffic Calming Circle • • 5,000 31
Modified Tee Intersection • • • • 32
Intersection Table • • • • 7,500 No 33
Modified Intersection/realignment • • • • • 34
Curb Radius Reduction • • • • • 35
Curb Extensions/Bulb outs • • • • 36
Short Intersection Median • • • 37
Gateway Treatment • • • 38
Diverters
Partial Closure • • • • No 39
Median Barrier • • • • No 40
Diagonal Closure • • • No 41
Street Closure • • • No 42
NON-INTERSECTION
Oval Median • • • 43
Raised Pedestrian Refuge • • • 52
Short Medians • • • • 51
Median on Curve • • • • 46
Median with Tree Wells • • • 45
Angled Slow Points • • • 1,000 (one-lane) 48
Chicane • • 3,000 No 44
Driveway Link • • • 3,000 No 47
Speed Hump • • 3,000 No 49
Speed Table • • • • 5,000 No 50
Woonerf • • 3,000 No 53
OTHER
Street Narrowing -Add Curbs • • • • 20,000 54
Centerlines • • • 5,000 55
Bike Lanes e . • 1,500 56
10n Street Parking • • • • • 57
City of Encinitas Neighborhood Traffic Management Program
Roundabout
Roundabouts are circular intersections with
channelized approaches.Entering traffic must
yield to circulating traffic. Pedestrian crosswalks
are marked one car-length from the entry and exit --
points. Roundabouts used in the traffic calming -�
program will be designed for a single lane of n
traffic on each leg. These roundabouts will vary C
in size, depending upon the number, type and size 0
of vehicles that will use them. All roundabouts are ,y
substantially smaller than large traffic circles ;,
often seen on the east coast. Traffic circles give n
priority to entering traffic and often use signals to
control entering traffic. Unlike roundabouts, large
traffic circles often operate at high speeds. Encinitas This illustration of a single-lane roundabout F
roundabouts will be designed for traffic speeds represents a typical design fora -
neighborhood street.
between 15 and 20 mph.
Street grades can impact roundabout design.
Techniques such as providing different grades on
eD
the high and low sides of the roundabout and
different elevations on each side of the central island
can be used to minimize the impact of street grades.
Locations
• Streets over 26' wide
• Local, collector and arterial streets
Roundabouts vary in size depending upon
• Intersections with 3 to 8 intersecting streets street characteristics, traffic volume, and
and adequate right-of-way other factors. The roundabouts above and
below are both in Fort Pierce, Florida.
• At sites where a small roundabout would fit,
but garbage trucks, school buses, or other
large trucks must turn, four options can be "
considered:
-Locate roundabout at intersection before or
after the one where large vehicles have to turn
-Reroute large vehicles to another intersection
-Add a truck apron -
-Use a raised intersection table instead of a
roundabout `a
City of Encinitas Neighborhood Traffic Management Program
Roundabout
Advantages Disadvantages
• Reduces number and severity of crashes • May require additional right-of-
compared to two-way and four-way stop way elf,
control and traffic signals �
• May restrict some turns by larger v,
• Simplifies intersections with more than three vehicles
intersecting streets • Some visually impaired .
• Reduces vehicle delay and queues pedestrians who are not trained to
use roundabouts may prefer
• Reduces pedestrian delay
signalized intersections n
• Shortens pedestrian crossings . Pedestrian walk routes are more C�
• Reduces pedestrian/vehicle conflict points circuitous than a standard
• Allows pedestrians to cross one lane of intersection •
traffic, wait in the refuge area for a gap in • Some on-street parking spaces ..
traffic, then proceed may be lost
• Increases likelihood of driver yielding to �*
pedestrians
• Eliminates conflicts between pedestrians and v
motorists when walk and green signals are Estimated Cost'
provided simultaneously
$130,000 to $200,000
• Increases intersection capacity
• Signal power and maintenance costs are
eliminated
• Useful life of a roundabout is approximately
2.5 greater than that of a signal system
• Eliminates driver confusion during power
outages
• Slows vehicles, including emergency - -
vehicles, without requiring them to stop
unless other vehicles or pedestrians are
present
• Emergency vehicles are not faced with Crosswalks are located approximately one
through vehicles unexpectedly running the car length from the yield line at
signal and hitting them at high speed. (2) roundabouts.
City of Encinitas Neighborhood Traffic Management Program
Traffic Calming Circle
Traffic calming circles consist of a raised island
located in the center of an unsignalized intersection.
Drivers maneuver around the central island rather ,•
than proceeding straight. Large vehicles are
permitted to turn left in front of the circle. Seattle, -
Washington,reports intersection crash reductions of
t7
93% following installation of these treatments. 0•
Traffic calming circles can be converted to small
roundabouts by adding painted or concrete splitter
islands and roundabout signing and markings.
Traffic calming circles can replace two and four n
way stop controls on local streets.
A raised island placed in the intersection
Locations creates a traffic calming circle.Most
vehicles travel around the circle as they
• Local streets under 26 would in a roundabout. Large vehicles CM
g
wide, with less than
such as fire trucks or moving vans are K
5,000 vehicles per day permitted to turn left in front of the circle.
• Intersections with 4 streets that intersect at
90-degree angles
x
Advantages
• Reduced vehicle crashes
compared to stop signs
• Slows vehicles, including
emergency vehicles, without
w_
requiring them to stop unless '
other vehicles or pedestrians are
present
• Landscaping reduces appearance
of a long stretch of asphalt
Disadvantages Estimated Cost:
$12,000 to $18,000
• Restricts larger vehicles
• Curb ramps may need to be relocated to
remove crosswalks from vehicle path
• Wrong-way left turns could be problematic
on busy residential or collector roads
City of Encinitas Neighborhood Traffic Management Program
Modified Tee Intersection
A curb extension added to the straight, through
street at the top of a tee intersection modifies the
travel path of through vehicles,forcing motorists to
slow to negotiate the curve. The minor street, which
terminates at the tee is controlled with a stop sign.
n
Locations Stap °
p Sign
Curve added
• Tee intersections
• Local and collector streets of any width
The illustration above shows how a typical n
tee intersection can be modified to deflect
Advantages the travel path of drivers.As demonstrated .
• Eliminates high speed through movements in the photo below the driver must make a .
turning movement to proceed through the
• Can reduce through traffic on through leg of measure. TO
tee
A�
Disadvantages
• Large through vehicles
may have some difficulty
maneuvering around the
median
M. ffi
Estimated Cost: µ
n
$20,000 to $29,500 '
City of Encinitas Neighborhood Traffic Management Program
Intersection Table
An intersection table elevates the entire intersection
to sidewalk level. Ramps on all streets force drivers
to slow as they enter and exit the intersection. The ""°""°""""""°lob
raised area is often brick or other textured material,
which can enhance its calming effect. If textured
materials are used, a smooth corridor should be
provided for people using wheelchairs and other
personal assistance devices. One or more bollards y
are placed on each corner to prevent vehicles from
cutting across corner space intended for use by
pedestrians. n
This treatment raises the entire intersection
Locations to sidewalk level to create a table. The "V" .
shaped markings in the illustration above are
• Local and collector streets of any width with placed on each street to alert approaching
fewer than 7,500 vehicles per day and not on drivers to the presence of ramps. The photo
below demonstrates how textures and colors
a primary EMS or bus route. can add visual impact and focus.
• Intersections of narrow streets
rD
where traffic calming circle or ;
roundabout would not fit
• Intersections where a
roundabout or traffic circle
would fit,but large vehicles .
such as school buses, garbage ,
trucks could not make turns
through the traffic circle/ ' +Il�li
roundabouts ,
Advantages
• Places a visual emphasis on the intersection Disadvantages
and pedestrians
•
• Minimizes loss of on-street parking, Increases turning difficulty
compared to a roundabout because drivers must go up a
ramp, turn, then go down a ramp
• Allows large vehicles to make unrestricted
• Emergency vehicles must almost
turns, compared to a roundabout
stop at every ramp
• Can be easier to construct than a roundabout
• Can provide accessibility solutions for Estimated Cost:
narrow sidewalks(3) $100,000 to $160,000
City of Encinitas Neighborhood Traffic Management Program
Modified Intersection/Realignment
At some intersections, streets do not intersect at 90
degrees. This creates a skewed intersection. At other Median added
sites opposing streets are offset from each other. _
Some intersections have several streets intersecting
on the same side of the street. In any of these
situations the alignment may create large expanses � n
of asphalt that enable drivers to turn at high speeds p'
and create long pedestrian crossings. The principle %
of a realignment is to reduce the area of asphalt, curbs extended
realign the streets, and square any skewed to reduce as-
phalt and re-
approaches. align curves n
Locations
• Local and collector streets.of any width Intersections can be realigned in many dif-
ferent ways to tighten curves, reduce the
Advantages amount of asphalt, or realign the streets. The rD
sample in the illustration above and photo r,.
• Lower turning speeds below demonstrate the principle of reducing 5
the area of asphalt to tighten the curves and
• Shorter pedestrian crossings create deflection to slow traffic.
CA
• Can discourage undesirable vehicle
movements
• May provide enough additional green space
to create a small park area
Disadvantages
• If not well designed, essential large vehicle
movements may be restricted �u�u
Estimated Costr
It is not possible to provide a cost estimate for this
type of design because the size of the intersection
street widths, angles of intersect and other factors
vary from site to site.
Alternate intersection redesign
with pedestrian crossing.
City of Encinitas Neighborhood Traffic Management Program
Curb Radius Reduction
A curb radius reduction is the reconstruction of an
intersection corner using a smaller radius. A smaller I
radius shifts corner space from the street to the
sidewalk area. ~
Tu in radius redud M
09
Locations Bulb outs eD
All streets of any width p•
• Intersections where there are low truck or I
other large vehicle usage {
Advantages
The dotted lines in the illustration above
• Slows turning vehicles indicate the original curb line. The turning
radius is reduced by extending the curb into
• Can discourage cut-through traffic by forcing the street. On streets with parking, the
a driver to turn at lower speeds. extensions can become bulb outs(see next
page for details). The photo below illustrates '"yt
• Shortens pedestrian crossing distances how the extension of the curb to tighten the Z:
• radius can shorten pedestrian crossing dis-
Provides more space for curb ramps
tances. �p
Disadvantages
• May be more difficult for some
larger vehicles to turn
Estimated Cost
$6,500 to $10,000 per corner
i
,r
j
City of Encinitas Neighborhood Traffic Management Program
Curb Extensions/Bulb Outs
Curb extensions, also referred to as bulb outs or
bump outs, narrow the street by extending the curb
into the parking lane, shoulder area, or curb lane.
For purposes of this handbook, these treatments will
be referred to as bulb outs. Bulb outs do not extend i,n9 radius reduced
into bike lanes. On-street parking impacts vary
Bulb outs ep
depending on existing practices and other site- �, n
specific conditions. - - -
Locations
• All streets over 26' wide with parking lanes, n
shoulder area, or overly wide curb lanes The dotted lines in the illustration above
indicate the original curb. Where on-street
• Downtown areas parking exists, the curbs can be extended to
the edge of the parking area to create bulb
• Near schools or other high-pedestrian outs. Where there is no parking, the radius
activity areas can be reduced. The photo below illustrates UQ
both designs.
CD
Advantages
• Shortens pedestrian crossings
• Pedestrians are more visible to
drivers because the bulb out allow
them to enter the crosswalk at a point
where parked vehicles do not block
the driver's view b
• Pedestrian can see approaching
vehicles more easily
• When the curb radius is reduced by
the bulb out, right turning vehicles
are slowed Disadvantages
• Improves emergency access and side street
Through vehicle speeds may not
visibility by eliminating illegal corner be substantially reduced unless
parking other measures are combined with
• Provides space for curb ramps, street bulb outs
furniture, and landscaping
Estimated Cost:
• Protects on-street parking areas
• Prevents vehicle travel in unused parking $10,000 to $16,000 per corner
areas
City of Encinitas Neighborhood Traffic Management Program
Short Median at Intersection
Short medians between travel lanes at neighborhood
intersections can slow turning vehicles and provide
pedestrians with a refuge area. A median on each
leg of an intersection prevents drivers from cutting
across the intersection along a very large radius and
forces drivers to make a slower, sharper turn around
the median. In situations where a wide exit lane
allows two vehicles to exit side-by-side,the median
can be used to narrow the street to a single narrow y
exit lane. This will discourage cut-through traffic by
A short median between travel lanes can
delaying drivers at the exit.
slow turning vehicles. The width of the n
median will vary depending on the width of
Locations the street. In the photo below, the curb on a?
the left side has been extended to narrow
• Local and collector streets over 26' wide the lane.Measures are often combined to
UQ
• Intersections where drivers make y
high speed left turns into a "
neighborhood
• Especially useful if drivers are
descending a hill before a left turn rn
• Useful to delay traffic exiting the
neighborhood
Advantages
• Can serve as a neighborhood
gateway
• Provides pedestrian with a refuge
area
Disadvantages
• Can restrict large vehicle turns
Estimated Cost:
$16,000 to $28,000
City of Encinitas Neighborhood Traffic Management Program
Gateway Treatment '
Gateways include a variety of treatments at the
entrance or entrances to a neighborhood or
community. Gateways announce arrival in a unique
place, such as a neighborhood of downtown. Many
gateways are purely aesthetic or informational and
have no impact on drivers unless reinforced with
additional treatments within the neighborhood. One C
form of gateway treatment is a short intersection
median that is enhanced with textured pavement to
create a physical sensation. Other examples include
signs in the center median, wing walls, non-movable n
gates, and arches over the roadway.
Locations A short median can serve as a gateway to a '
neighborhood. The illustration above shows UQ
• Local and collector streets over 26' wide how texture can be added. The large tree in
• Significant entrances to neighborhoods or the median below is another illustration of a rD
commercial areas neighborhood gateway feature.
• As a divider between
commercial and residential
areas on the same street
i
Advantages
• Separates arterial street
type environment from a ' y
neighborhood environment - - °•,
• Strengthens neighborhood °
identity r�
• Can improve wayfinding ~�
by providing a landmark d
Disadvantages
• Limited effectiveness in changing driver
behavior
Estimated Cost:
$40,000 to $59,500
City of Encinitas Neighborhood Traffic Management Program
. Partial Closure '
One-half of a local street can be closed at a
neighborhood entry or exit point with curb L extensions, bollards, or other treatments to restrict
access into or out of the area. Half closures can be
set up in various configurations to complement ►.�
CA
treatments on the other side of the intersection. _---_
Partial closures are rarely used because they create C
circuitous routes for those accessing adjacentK .r;.;,
properties. Traffic is increased on nearby streets.
Locations
• Local and collector streets of any width and
These two illustrations show how a street
not on a primary EMS or bus route can be partially closed to prevent traffic
►r.
At intersections on acut-through route from continuing straight through. Various
• configurations can be designed to address
cut-through concerns.
Advantages
• Eliminates cut-through traffic in one direction
c�
• Allows two-way traffic on the remainder of
the street , ..
• Two-way bicycle access can be preserved
Disadvantages -----------------------
• Restricts resident access to their property
• Inhibits access by emergency vehicle
• May cause confusion until maps reflect the
change
• Increases traffic volumes on other "
streets
• Can impede citywide traffic
circulation
Estimated Cost:
$26,500 to $42,000
This partial closure allows traffic to exit
the street, but the entry lane is blocked.
City of Encinitas Neighborhood Traffic Management Program
Median Barrier
A raised median between travel lanes that can extend
across the intersection to block left turn and through
movements from cross streets. It is a diversion tool to
prevent vehicles from passing through one
CD
neighborhood, crossing a major street, and continuing
into another neighborhood to create a cut-through n
route. Residents and service providers using that
O
intersection can enter and leave only by turning right _ 0
into or right out of out the street. All barriers that y
restrict traffic flow must be used sparingly to preserve
convenient access and distribute traffic evenly. n
A raised median through the intersection
restricts access to right turning vehicles, >y
Locations pedestrians, and bicyclists.
• Local and collector streets s -- ---
of any width and not on a
primary EMS or bus route.
A�
• Intersections along cut- .>.
through routes that cross
major streets
Advantages
• Median can provide a
pedestrian refuge island
• Prevents cut-through traffic
Disadvantages
• May restrict vehicle access between
neighborhoods
• Restricts resident access to their property Estimated Cost:
• Inhibits some access by emergency vehicles $16,000 to $22,500
• Increases traffic volumes on other streets
• Can impede citywide traffic circulation
• May cause some confusion until maps reflect
the change
• Trash and silt may accumulate
City of Encinitas Neighborhood Traffic Management Program
Diagonal Closure
A raised median can be installed diagonally across
an intersection to prevent through movements and
divert traffic onto other streets.These and other
partial closures are rarely used because they create
circuitous routes for those accessing adjacent
properties and traffic is increased on nearby streets.
When used,pedestrian and bicycle access can be s o
preserved through the diagonal median.
}.
Locations
• Local streets of any width and not on a
primary EMS or bus route. A raised median installed diagonally a?
eliminates straight through vehicle traffic. F
Advantages The breaks in the median shown in the
illustration above depict curb cuts to allow TO
• Eliminates through traffic bicyclists full access.
• Shortens pedestrian
crossings
• Can include a bikeway , k
connection
Disadvantages
• Restricts resident access to ` w
their property
• Restricts vehicle access
between neighborhoods y
• Inhibits access by
emergency vehicles
• May cause confusion until maps reflect the
change
• Increases traffic volumes on other streets
• Can impede citywide traffic circulation
Estimated Cost:
$29,500 to $44,000
City of Encinitas Neighborhood Traffic Management Program
Street Closure
The most severe traffic calming treatment is a street I -
closure. A closure prevents all vehicle access into or ,
out of the street at that location and creates a cul-de-
sac. Bicycle and pedestrian access can be retained.
Bollards,barriers, and curb extensions are some of
the methods used to close streets. Street closures are — --- - ----- --------
rarely used because they create circuitous routes for �.
those accessing adjacent properties. Traffic is _#� *� ,
increased on nearby streets. It will be difficult to w
obtain approval for a closure due to the severe
impact on neighborhood and citywide traffic
circulation patterns. Total closure of streets is rare because of
adverse impacts on other streets in the
neighborhood. When streets are closed, it
Locations can be done in a way that adds value to the
surrounding area.In the photo below, a
• Local streets of any width former street was converted to a linear park
with a trail.
• Streets where few
properties are accessed
from the street
r-r-
Advantages
• Eliminates through traffic
• Reduces vehicle speeds
in remainder of closed -`
street
• Closed street can be used
for a park or playground
in some cases
�r
Disadvantages
• Restricts resident access to their property
• Increases traffic on other
• Inhibits access by emergency vehicles neighborhood streets
• Increases travel distances for residents, . Eliminates an entrance to the
visitors and service providers neighborhood
• May cause confusion until maps reflect the
change Estimated Cost:
$15,000 to$22,000
City of Encinitas Neighborhood Traffic Management Program
Oval Median
A raised, oval-shaped median placed between
narrow travel lanes forces drivers to slow to
maneuver around the median. It may be necessary to
extend curbs in advance of the median so driver —
cannot proceed straight through the curve. In such —
cases, the extension can become a location for trees
or other landscaping features. The impact of the
oval median,like other treatments, is improved by
provision of landscaping. The median can also
provide an island for a pedestrian crossing. '
b
Locations
• Local and collector streets over 26' wide
Advantages _ n
• Can be designed to different speeds p
• Can provide refuge for pedestrians and y
bicyclists crossing the street
A raised median in the shape of an oval is n
Disadvantages combined with a realigned curb to create a
curve in the vehicle travel path. The center is
• Requires careful design to achieve real speed often the site of a large tree or other highly
reduction visible feature.
• Can restrict large
vehicles
Estimated Cost:
$59,500 to $90,000
v
City of Encinitas Neighborhood Traffic Management Program
Chicane
Chicanes are created using curb extensions that
alternate from one side of the street to the other to
create a single travel lane with S-shaped curves.
Chicanes are sometimes referred to as deviations, ,
serpentines,reversing curves, or twists. Chicanes rely
on a curvilinear path and potential conflict between
opposing traffic flows to reduce travel speeds. The
design must discourage drivers from cutting straight
paths across the centerline or testing their skills on the
curves or speed reductions will not occur. Their use is Id
confined to lower volume streets because traffic can i Z
pass through the chicane in one direction only. 4 p
Locations
Curb extensions on alternating sides of the
• Local streets less than 26' wide and not a street create a winding travel path wide
primary EMS or bus route
enough for one vehicle. If another vehicle
approaches, they must wait until the chicane p
• Streets with less than 600 vehicles per day is clear before entering.
• Two-lane, two-way streets
• One-lane, one-way streets
Advantages
• Potential for higher degree of
speed reduction �a
Disadvantages x r a
• It may be necessary to ban
parking within the chicane
• Most effective where traffic ---- —
volumes are balanced in each direction
• Trash may accumulate
• Bicyclists must merge with vehicles to pass
through
Estimated Cost:
$12,500 to $18,500
City of Encinitas Neighborhood Traffic Management Program
Median with Tree Wells
A median island combined with trees wells creates a
chicane effect on streets where two-way traffic must
be maintained. A curvilinear path is created with
curb extensions similar to those used for a chicane, 4
but a median is installed in the center of the street to
separate travel lanes. The curb extensions are 4
generally planted with trees to increase the visual
impact of the treatment.
Locations
• Local and collector streets over 32' wide '� C
Advantages
• Enables two-way traffic
• Beautifies the street I
O
Disadvantages y
• It may be necessary to ban parking between A raised median with tree wells on either
.f a.ff
end can create an effect similar to that o
the tree wells
chicane,yet still allow two lanes of traffic.
• Can impact access to driveways
• Trash accumulation ,
• Bicyclists must
merge with vehicles
to pass through
t �
Estimated Cost:
a
$24,000 to $36,500
-- ti
City of Encinitas Neighborhood Traffic Management Program
Median on Curve
Medians of various widths can be installed on
curves to prevent vehicles from crossing the
centerline to facilitate travel at higher speeds. - '. -- --. --=
Openings in the medians may be necessary to
provide access to driveways. Raised pavement
markers can be used on curves to create the effect of l ld
a median when site constraints or other factors, such
as emergency vehicle access,prevent use of a raised
curb.
1
Locations
0
• All streets over 26' wide
B
1..1.
A raised median on a carve prevents vehicles
Advantages from crossing the centerline. The opening in
the median allows driveway access for rA
• Stops drivers from crossing centerline on adjacent homes. n
curves
• Prevents passing
movements on curve
• Reduces travel lane width
• Can provide pedestrian n
refuge and shorten • - `+
If �.
crossing distance
.p.. . UQ
Disadvantages
• Can make travel around
the curve by large
e
_
vehicles difficult W
f.
• Can restrict access to
some driveways unless
openings are provided within the median at
each driveway
• Trash may accumulate
Estimated Cost:
$13,000 to $20,000
City of Encinitas Neighborhood Traffic Management Program
Driveway Link
A driveway link converts a straight, two-lane street
into a winding one-lane street lengths over distances
of up to 200 feet.When carefully landscaped,the
street appears to be closed. The narrowed road space
and landscaping create a park-like appearance that
enhances the street and facilitates increased -
pedestrian activity in that area.
Locations
• Local streets of any width = 'r
• Street with less than 1,500 ADT = =?
Advantages
• Reallocates portions of the street to other y yg
public uses
• Creates the impression of a closed street, y
while maintaining the link between
neighborhoods.
Disadvantages W
• Length of treatment is limited by cost The drawing above shows how a section of a .
two-lane street can be converted to a single
• Drivers must yield to each other travel lane. Drivers approaching the link ro
must wait if a vehicle is approaching from
• Impossible to street sweep the other direction..
Estimated Cost
$58,500 to$99,000
City of Encinitas Neighborhood Traffic Management Program
Angled Slow Points
Triangular islands constructed on both sides of a
street narrow the vehicle travel path a add a curve
to a straight section on street. A short median is 1�
installed between the travel lanes of two-lane slow Triangular
points. Drivers must slow to negotiate the turns Island
needed to maneuver through the curve created by :R
the islands. On single-lane slow points drivers
must yield to oncoming traffic. A raised median
can be added to slow points for added deflection. Median
Locations Z
• Local and collector streets over 26' wide
and not on a primary EMS or bus route Angled slow points add a tight curve to an e4.•
otherwise straight street.A median is used rD
• Single lane slow points on streets under 26' on two lane angled slow points to ensure rA
wide with fewer than 3,000 vehicles daily drivers can't "straighten"their travel route n
by crossing the centerline. �•
Advantages
• Create horizontal deflection while
maintaining passage for large vehicles
Disadvantages
• Bicyclists must merge with vehicles to
pass through " R. Q q
• Trash may accumulate
Estimated Cost:
Speed table
Two lanes - $12,500 to $18,500 w Single travel
Single lane - $10,000 to $15,500 'o lane
Single lane w/speed table—$13,000 to $19,000
+ r
i
} V
The illustrations on the right show how angled slow
points can also be single-lane. Both illustrations force 1
traffic through a narrow, one-lane angled opening. The "
+
illustration on the right shows how a raised speed table I
can be added to a single lane angled slow point to
create vertical deflection. '+.
City of Encinitas Neighborhood Traffic Management Program
Speed Hump
Speed humps are asphalt or concrete street surfaces
that span the width of the street and.are raised and
slightly rounded.When used in Encinitas, they are 3
high and approximately 12 feet long. Speed humps
create a driving surface that is uncomfortable at ---------' - '---'—'—'-
higher vehicle speeds, especially when used in closely
spaced pairs. The discomfort prompts drivers to slow
in advance of the hump. Speed humps have a minimal
impact on vehicles with good suspension systems and
a severe impact on large vehicles such as buses,
garbage trucks and emergency vehicles. Speed humps
will only be considered where there are no other Speed humps are slightly rounded areas that �
span the width of a street to create a 3 inch
viable alternatives or where impacts are restricted to rise in the street surface. .
the residents of that streets only, such as
on a cul-de-sac.
n
Locations o•
• Local streets under 26' wide and
not a primary EMS or bus route A�
• Streets with less than 3,000 ADT n
Advantages
• Bicyclists do not have to move out
of their travel path to cross
Disadvantages ,
• Emergency vehicles forced to almost stop at Uncomfortable for people with
each hump back injuries or other chronic
• Vehicles braking and accelerating create noise painful physical conditions(3)
• Can damage vehicles at higher speeds • Restricts mobility for people
using wheelchairs if installed
• Limited affect on some vehicle types where there are no sidewalks
• May detract from residential property values
Estimated Cost:
• Uncomfortable for passengers of buses and
ambulances $5,700 to $8,300
City of Encinitas Neighborhood Traffic Management Program
Speed Table 1
A speed table is an elevated, flat street surface with
ramps on both sides to create a grade change on
both sides of the table.A steeper grade on the ,4
approach and departure ramps will produce slower
speeds. The sloped ramp leading to the platform is --- -----
less jarring for vehicle occupants than a speed
hump. A change in surface color and/or texture on s '
top of the speed table can increase its effectiveness.
Speed tables are effective tools for providing high
visibility crosswalks schools, trails, and other mid- -
block crossing locations where slower speeds are
A speed table is a flat surface that is slightly Z
desirable. They can be combined with bulb outs to higher than the street. The "V"symbols in
shorten pedestrian crossing distances and prevent the drawing above illustrate marking to alert ,
drivers from avoiding the full impact of the drivers to the ramps leading to the table. The
treatment by driving with two tires in the gutter. flat surface on a speed table makes it well
suited for a crosswalk. The photo below C
shows a speed table with a median. n
Locations o•
• Local and collector streets of any y
width not a primary EMS or bus
route
n
• Streets with less than 5,000 ADT
• Marked, unsignalized mid-block II �
pedestrian crossings
UQ
Advantages
c�
• More easily traversed by large
vehicles than speed humps • Can damage vehicles at higher
• Provides a defined pedestrian crossing area speeds
Improves visibility between pedestrians and • Vehicles braking and accelerating
drivers create noise
Raises vehicles to pedestrian level • Can be uncomfortable for people
• Eliminates need for a curb ramp at the
with back and neck problems,
though less jarring than speed
crossing
humps c3>
Disadvantages Estimated Cost:
• Emergency vehicles forced to almost stop at $24,000 to $36,500
the ramps
City of Encinitas Neighborhood Traffic Management Program
Short Medians
Raised medians of varying widths and lengths can
replace two-way center turn lanes or reduce the width
of overly wide streets. Medians can be designed to
allow drivers full access to driveways. ~`_ ,
f _ k
Location r
• Collector streets
• Streets over 26' wide
E
t
3
Advantages
• Eliminates turning conflicts in center turn
lanes i •
s �
• Eliminates use of center turn lane for passing K
• Can provide pedestrians with refuge area
• Can be used to narrow travel lanes C
Raised medians of varying lengths can be
designed allow drivers to turn into y5
Disadvantages driveways.
• Speeds may not be reduced because no n
deflection is created C�
Estimated Cost: .
cr
$16 500 to$25,500 a
y
a�
City of Encinitas Neighborhood Traffic Management Program
Raised Pedestrian Refuge
Pedestrian islands are short medians placed in the
center of the roadway separating opposing lanes of Bulb out
traffic. The island allows pedestrians to cross one-
half of the street, wait outside the traveled way until
vehicular traffic yields or there is a gap in traffic
f:
that allows them to complete their crossing,then
Crosswalk
complete their crossing. Wait and crossing times are
decreased. Trees will small trunks should be planted
in the refuge on both sides of the crosswalk to
increase visibility of the treatment.
Other treatments such as bulb outs, narrow travel Raised I o
lanes and others appropriate for the street can be Median
combined with the island to achieve desired speeds °
and improve motorist yield behavior. Pedestrians can cross one-half of the street
at a time when a raised median is used to
provide a crossing island.. n
Locations c
Local and collector streets over 26' wide
Advantages
n
• Provides pedestrians with safer, more
convenient crossings
• Breaks up the continuous nature of the street •
UQ
Disadvantages
• Must be combined with other treatments to ai•
In the photo below a speed table and bulb
create deflection
out have been added to the pedestrian island.
Estimated Cost: �, t
CA
$23,000 to$34,000
v
� q
vp
City of Encinitas Neighborhood Traffic Management Program
Woonerf
The term woonerf is used to describe public right-
of-way space that is shared by vehicles and people
not in cars. The street may be designed as a play
area or other public space with a single 10-foot wide
lane that wanders through the former street
alignment. Asphalt is usually replaced with bricks or
other textured materials which are graded to direct
water to low areas where drains are _.
provided to collect water.
Y
Locations + Z
• Local streets under 26' wide x
and not a primary EMS or
bus route 4.
• Streets with less than 5,000 rD
ADT
MR
Advantages
• Provides very low vehicle ►"'''�
speeds n
• Creates a shared space for everyone to use E.
Disadvantages
OM
• Expensive
Estimated Cost
It is not possible to provide a cost estimate for this
type of design without site specific details.
City of Encinitas Neighborhood Traffic Management Program
Narrow Street: Add Curbs
Streets without curb and gutter can create the r -
appearance of a high-speed rural road that
encourages some drivers to speed. Adding
curb and gutter changes the appearance of
the street to a local street and prevents
vehicles from encroaching on unpaved
shoulder area.
Street widths can have a significant impact
on vehicle speeds. The American Association
of State Highway and Transportation
Officials (AASHTO) establishes guidelines
for local streets 26-feet wide. This face-of- These Encinitas streets illustrate how adding curbs
curb-to-face-of-curb width provides space for and gutters changes the appearance of the street.
a 12-ft center travel lane and two 7-ft parking
lanes. Parking on one side of the street can be
allowed on streets as narrow as 20 feet.
These streets function effectively because
drivers can yield to oncoming cars by pulling V
into driveways or parking spaces that are not
occupied. Reduction of travel lane width to
ten feet may also yield some reduction in
speeds. o
Location
• Local and collector streets
As shown in the image below, some communities pro-
vide a planter strip between curbs and the sidewalk n
Advantages area. Trees and landscaping are closer to the street.
• Can help lower speeds y„ i
• Improves drainage �
Disadvantages
a�
• High cost
rD
• Lack of universal impact on drivers
Estimated Cost:
Curb and Gutter- $35 linear foot
City of Encinitas Neighborhood Traffic Management Program
Centerlines
Marking centerlines that divide
opposing travel lanes provides drivers
with a clear indication of their travel
width, location and path of on-coming
vehicles. Removing or not marking a r ; _
'Fr
centerline creates uncertainty and
helps lower vehicle speeds. This ;
treatment may be combined with
marking stripes along the edges of the
street for parking or for bike lanes to
yield a greater impact.
Location
• Local streets of any width
Advantages
• Low cost technique
• Reduces maintenance costs
Disadvantages
• May not be effective on all drivers
Estimated Cost: f°
$1.50 per linear foot to remove centerlines and add A
white lines on street edges
>y
�Q
rr-
City of Encinitas Neighborhood Traffic Management Program
Bike Lanes
Bike lanes consist of two stripes that ;.
define the space on the street for
riding bicycles. The minimum width
for a bike lane adjacent to a parking
lane or curb is five feet. If there are
no curbs and gutters,the minimum
width is four feet. The stripe can
narrow the travel lanes and give the
overall street a more narrow
appearance. They provide many
other benefits to bicyclists and
pedestrians,but because they do not
deflect the vehicle travel path their
Bike lanes are added to a wide street with a median in the
impact on speeds may not be photo above. Below, bike lanes were added to a two-lane
significant. street without a median..
Location
• Collector Streets
• Streets with more than 1,500
ADT
• As designated in the Bikeway
Master Plan o
Advantages . .
• Provides separate riding space
for bicyclists n
• Narrows appearance of the
street
• Provides lateral separation between Estimated Cost: '
CM
pedestrians and traffic $1.50 per linear foot to remove
• Provides a buffer area between those center line and add white lines on
entering and exiting parking spaces and the two edges
moving traffic
Disadvantages
• Not effective on all drivers
City of Encinitas Neighborhood Traffic Management Program
On-Street Parking
Vehicles parked on the street effectively
reduce pavement width and can reduce
vehicle speeds. Drivers are sometimes
reluctant to park on the street because
they fear their vehicle will be hit. Bulb-
outs and tree wells along the street can
protect parked vehicles while improving
visibility between pedestrians and
motorists.
Alternating on-street parking from one
side of the street to the other on narrow
streets creates a chicane-like effect.
The street above is 30'wide from curb-to-curb. The
Parallel or angled parking can be used parallel on-street parking narrows the travel area of the
alone or in combinations. This treatment street. In cases where additional parking is needed, such
can be used in combination with as parks, diagonal parking may be feasible if street width
landscaping to beautify the street and is adequate. Bulb outs help prevent drivers from using
parking areas as travel lanes when no vehicles are
screen parking areas. parked.
Marking of parking spaces is not necessary
on collector roads or local streets unless
the streets are wide and there is a need to
narrow the street and encourage on street
parking. On these streets a single line is all o
that is required.
Location
• All streets n
Advantages
• Reduces street width
ft4
• Provides convenient access to abutting
properties
Disadvantages
• May obscure pedestrians from drivers' view
City of Encinitas Neighborhood Traffic Management Program
5.0 Design Considerations
This section is oriented to engineers and design- on nearby areas or the overall traffic circula-
ers who will assist the citizens of Encinitas with tion patterns.
the design and implementation of their neighbor-
hood traffic plan. Citizens will rely upon the in- The needs of all who share the roadway envi-
formation and tools provided in preceding sec-
ronment, including bicyclists,pedestrians,
tions and during neighborhood meetings to de- transit, delivery vehicles, emergency service
velop a plan to address their concerns. Their sug-
providers, and passenger vehicles must be
gestions must be reconciled with design consid- considered and balanced. Special needs for
erations to create a plan that reflects their wishes visually impaired people or those using
wheelchairs, walkers, and baby strollers must
but is compliant with guidelines and practices of
be accommodated. Existing landscaping,
the engineering profession.
neighborhood character, and many other con-
The treatments in the Toolbox include designs textual elements must be factored in, and the
that create horizontal or vertical deflection to public input is of great importance in any de-
require motorists to slow down,improve pedes- sign. Normal procedures including environ-
trian crossings,or address other concerns ex- mental review and Coastal Development per-
pressed by the public or revealed by safety data. mitting required for construction plan ap-
The Toolbox includes a wide variety of treat- proval must be followed.
ments to address a range of problems in diverse
environments with variable topography and 5.1 Project Development
street widths. Treatments, landscape and street Each project will include public input as de-
scape elements, traditional access management scribed in Section 3.0,Process. This collabo-
techniques such as raised medians and right-in, rative approach to traffic management en-
right-out turn lanes,and lane markings can be sures that the designer has a complete under-
used in a variety of combinations to address standing of resident concerns. The final pro-
speeding and high levels of cut-through traffic ject is more likely to be endorsed by most
on neighborhood streets. Treatments are gener- residents when they have assisted in the de-
ally designed to fit into existing rights-of-way velopment of the conceptual plan.
with minimal new infrastructure construction,
utility relocation and repair. The design process starts following the
Neighborhood Workshop described in 3.5, on
Traffic management in a neighborhood must be page 17. During this meeting, citizens would
holistic. That is,the placement of each treatment have identified their concerns,learned of po-
must solve problems throughout the neighbor- tential solutions, and developed a conceptual
hood, and not move the problem from one loca- plan for their neighborhood. The first step of
tion to another. The designer must consider the evaluating their plan is to conduct a site in-
impacts that traffic calming treatments may have spection to review the location of each traffic
City of Encinitas Neighborhood Traffic Management Program
1
calming treatment,take notes and check the Spacing
impact on driveways,drainage structures, Each traffic calming treatment has an effective
trees, curb lines or lack of curb, utilities and range beyond which drivers return to their pre-
overhead lights., vious driving habits.Treatments must typically
be installed at intervals of 400 to 800 feet to
5.2 Overall Design Review obtain a consistent change in driver behavior.
Variable conditions in the roadway environ- Treatments spaced more closely than 400 feet
ment make it essential that traffic calming apart could evoke dissatisfaction among resi-
treatments be designed for each specific dents. Spacing treatment over 800 feet apart
site,rather than done as a"cookie cutter" will provide drivers with an opportunity to
approach. The designer needs to experience reach high speeds. Varying the type of traffic
the problem by undertaking field reviews to calming measure requires drivers to adopt dif-
gain a complete understanding of the prob- ferent driving techniques at each location.
lem and to review site conditions. Follow-
ing the site review for each treatment the Driveways
designer uses the basic layouts given in the
Traffic
following pages to confirm that the treat- fic calming treatments need to be located
ment chosen by the residents is the best away from driveways, or in such a way that
Turn-
treatment for each location and if for what- they do not completely block driveways. Turn-
ever reason, drainage problems, utility con- ing restrictions to ingress and egress are some-
flicts, negative impact on driveways etc., times necessary. Driveway access at round-
they can change the recommended treat- abouts can be preserved in many designs, and
ment to a more suitable treatment for that reversing into a roundabout from a driveway,
location. in the same manner as drivers have tradition-
ally backed into traffic, may be acceptable on a
low volume street.
Design Speed
Design speed is a critical element of each Intersections
traffic calming treatment. Establishing de-
sign speed allows each treatment to be de- In most instances, capacity at neighborhood
signed according to road function and the intersections.where traffic calming treatments
problem to be treated. The table below sum- are planned is not an issue. Topography, drain-
marizes suggested design speeds for the age, driveway location,radii, street width can
traffic calming treatments based on func- affect treatment design. It is important that ve-
tional classification of the roadway. hicle turning requirements are checked. The
use of AutoTurn is encouraged to check each
Roadway Classification Design Speed intersection design.In some cases the treat-
Local 12-15 mph ment suggested during the neighborhood work-
Collector 15—20 mph
shop may need to be changed. In this case,the
designer should document and explain the rea-
City of Encinitas Neighborhood Traffic Management Program
1 �
son for the change during the follow-up meet- Traffic Signals
ing. Traffic signals are not a traffic calming treat-
In the past, some intersections were con- ment. The function of a traffic signal is to
structed at skewed angles and with very large transfer time from one street to another. Anec-
radii. Some have large areas of asphalt and ac- dotal evidence suggests that drivers tend to
.commodate high speed turning movements. speed up along their route to compensate for
The consequence to this intersection design is time spent waiting at a signal or in attempts to
that drivers who enter a neighborhood at high avoid a"stop" signal. Signals can, however,
speeds tend to maintain or increase their speed affect traffic calming'in nearby areas. By
as they move further into the neighborhood. modifying existing traffic signal phasing or
Redesigning to AASHTO guidelines may in- duration on the collector roads, cut-through
volve realigning the intersection angles to as traffic can be averted. For example,the green
near as possible to 90 degrees, minimizing the time on the arterial or collector road that is par-
area of asphalt, and channelization to minimize allel to a cut-through route can be increased to
conflicts. Examination of existing vehicle encourage drivers to stay on the main road.
paths can help determine the extent of asphalt Signals can also be modified at the entrance to
needed. Excess asphalt can be changed to land- a subdivision to reduce the green time on a
scape space. Provision of a raised median on designated approach and discourage cut-
some or all of the intersection approach legs through traffic.
can help slow traffic, reduce the openness of
the intersection and provide pedestrians with Emergency Vehicles
refuge islands. Often the addition of a median
is more effective than simply reducing the.turn Traffic calming treatments that are effective in
radii.The use of vehicle turning templates can slowing or diverting vehicles have the same or
help determine the best design approach. greater impact on emergency vehicles. Sudden
vertical deflection can be jarring and uncom-
fortable for passengers in fire trucks,which are
Turning Templates longer and have stiffer suspension than passen-
The use of templates for the design vehicle ger vehicles. Vertical deflection treatments
when designing traffic calming treatments is may have an even greater effect on ambulances
essential. Determine which vehicles must that are transporting patients.
travel along the route to select the appropriate
Most traffic
template. In some cases it maybe practical to
calming treatments have little or
make a minor adjustment to a vehicle's route no impact on emergency response time be-
so the design does not have to accommodate an cause they are mostly located in the last link
occasional large vehicle. This should be a City (street)on an emergency response route.
and neighborhood decision. Design elements can be added to treatments to
improve emergency vehicle maneuvering and
to allow emergency access. For example, traf-
City of Encinitas Neighborhood Traffic Management Program
1
fic circles can be built with mountable aprons. Raised Islands
which allow fire trucks to pass through an in-
tersection without compromising the measure's . Raised islands are to be constructed to ac-
effectiveness in slowing passenger vehicles. ceptable standards within typical minimums
Emergency service providers are supportive of of 18 inches in width and.a minimum area of
the program and must be consulted with to pro- 50 square feet. AASHTO guidelines suggest
vide input on any traffic calming design,i.e., offsets for approach vehicles are important to
where mountable curb maybe required to ac- provide vehicles with some forgiving space.
Raised islands can be solid concrete pinned to
commodate their vehicles.
the asphalt or the road pavement can be exca-
vated and full depth curbing provided. The
Americans with Disabilities Act(ADA) interior of the islands can be filled in with
The Americans with Disabilities Act,42 plain or colored and stamped concrete,paved
U.S.C. 12101 et seq.,requires removal of ar- with brick, or landscaped. The inclusion of a
chitectural barriers to provide access for dis- gutter can permit drivers to take a slightly
abled people. Federal regulations mandate in- faster path through the treatment. Where pos-
stallation of curb ramps or slopes to accommo- sible the gutter should be included as part of
date access to streets.Any alteration to a facil- the travel way when determining deflection.
ity which may affect its usability, such as in- If the gutter is not needed,i.e. the road slopes
stallation of a physical device in the street or a away from the island,then curb only around
change to the curbing or sidewalk,triggers the the island is preferred.
obligation to construct curb ramps or other ap-
propriate accommodations for the entire facil- Drainage
ity. Most traffic calming treatments fit this cri-
teria and the designer should be aware of any Design of traffic calming treatments must
required ADA improvements at the start of de- address drainage, as many traffic control
treatments can impede existing drainage
sign. flows and patterns. An exception to City stan-
dards can be made to allow construction of a
Sidewalks raised island within the pavement utilizing a
Sidewalks should be constructed to comply checkered steel plate with a non-slip surface
with current City standards and the Recrea- that is bolted down or a 4 to 6 inch pipe that
tional Trails Masterplan. The Masterplan iden- is laid in the gutter. The sidewalk is then ex-
tifies locations where pedestrian paths can be tended over the pipe. This is a typical drain-
provided in lieu of sidewalks. New sidewalks age solution for a bulb out or speed table at a
should follow AASHTO guidelines that rec- pedestrian crossing. The length of the metal
ommend placement of sidewalks as near as plate or pipe should be greater than the width
possible to the right-of-way. Locate sidewalks of the crosswalk or sidewalk to accommodate
one foot from the right-of-way line to allow for pedestrians or people using wheelchairs that
variations in fence lines and to accommodate may approach the crossing at an angle. The
overhang from plants. sidewalk or curb extension should also be
City of Encinitas Neighborhood Traffic Management Program
1
landscaped in such a manner that it discourages the reasons described above.
pedestrians from crossing outside of the path-
way created by the metal plate.If the curb ex- Traffic calming treatments installed on streets
tension is in a site where there is no pedestrian with unimproved shoulders generally do not
crossing,the 18 inch gap created by the gutter have a significant impact on drainage. The de-
shall be left open. This exception is acceptable signer should still exercise care in these situa-
for the installation of traffic calming treatments tions to avoid creating a drainage or erosion
with existing streets only. New streets must problem.
provide adequate drainage infrastructure in
conformance with City standards. Fire hydrants and water meters
The flow area along the roadway may be con- Existing water meters and fire hydrants should.
strained to the width of the gutter when a be relocated to conform to current standards
raised island is added. When water is con- whenever the curb and sidewalk are relocated
strained to the gutter, the upstream flow area for traffic calming treatments.Water meters for
may become wider and water will eventually landscape irrigation should be installed wher-
flow around the raised island. For raised is- ever landscaping is included in a traffic calm-
lands designed within these guidelines as a ret- ing measure. Backflow prevention devices are
rofit to an existing street, an exception to the recommended to be located in areas which are
Storm Drainage Standards can be made. A least impacted by pedestrian traffic.
bulb out or speed table is designed to slow traf-
fic and does not lose that characteristic during Visibility
rainstorms. Traffic is expected to be moving at
a speed that would preclude hydroplaning Traffic calming treatments must be clearly
through pooled water. The designer should re- marked and signed in compliance with the
fer to the San Diego County Flood Control MUTCD or according to the City's conven-
District Design and Procedures for additional tional practices..The MUTCD includes signs
guidance. that are standard, or mandatory, and signs that
are optional. Careful discrimination must be
When the gutter is directed around a bulb out, used in the selection of signs in order to pre-
the runoff flow area can extend further into the vent confusing sign clutter that could arise if
travelway. In contrast, a median constructed all possible signs are installed.
within.an existing roadway can direct vehicles
closer to the gutter and the gutter flow. Both Concrete curbs dictate vehicle paths in traffic
calming treatments and should provide drivers
conditions shall be acceptable under these
guidelines because operating speeds are ex- with a smooth travel path free of kinks or sud-
pected to be low. A speed table obstructs most den changes in direction. Curbs should be set
of the travelway and will also obstruct the gut- back from painted gore areas on approaches to
ter flow, which are exceptions to the San Diego
most traffic calming treatments.
County Flood Control District Design and Pro- Raised pavement markers should always be
cedures.These exceptions are acceptable for used to improve night visibility of traffic calm-
City of Encinitas Neighborhood Traffic Management Program
1
ing treatments. Raised pavement markers can sight triangles. Mid-block traffic calming
serve two purposes in some traffic calming treatments may contain denser plantings than
treatments. They delineate the road centerline at intersection treatments because sight trian-
during after dark hours. When closely spaced, gles are usually less critical on straight road-
the markers discourage drivers from crossing way sections. Plantings with low water needs
the centerline at any time. are preferred to limit saturation of base and
subgrade road materials.
Lighting and landscaping must also be incor-
porated into traffic calming treatments to en- Trees can be planted in medians,bulb outs,
hance visibility and ensure that drivers can planter strips, and near the edges of most
identify the object and respond appropriately.
It should never be assumed that the existing
lighting is adequate. Some treatments may re-
quire additional safety lighting at the discretion When selecting the location and size of
of the City Engineer. Increasing the lighting to trees, the designer or reviewer should con-
suitable levels could mean installing additional sider the following guidelines to determine if
poles, increasing the wattage of existing street mature size and location of plant material will
lights, or modifying light fixtures. affect safety:
1. Draw the approaching vehicle
Landscaping
The City of Encinitas requires that traffic calm- 2. Draw the driver's head within the stan-
dard position within the vehicle
ing treatments be appropriately designed to
meet high aesthetic values. Appropriate land- 3. Draw the tree at its mature trunk and
scaping is highly encouraged, together with canopy thickness
necessary irrigation and maintenance provi-
sions. Landscaping is an essential element of 4. Draw the conflicting vehicle
traffic calming because barren, open streets 5. Draw two lines from the approaching
encourage drivers to speed. Trees and shrubs driver's head toward the conflicting vehi-
enhance driver identification of traffic calming cle that just touches each side of the tree
treatments,provide long-range visibility, en- truck
hance neighborhood appearance, and visually
narrow streets. 6. If the sight triangle that is developed cov-
ers less than 50 percent of the conflicting
Landscape elements for traffic calming treat- vehicle, then the driver obviously will not
ments must be selected to support a slow-speed lose sight of it. Even at 75 percent block-
environment. Limit shrub height to 2 foot, 6 age the conflicting vehicle is visible to
inches in areas with driveways or pedestrians,
the driver. If the coverage is greater the
simple solution is to move the tree sev-
or where sight-lines are critical. Careful selec-
tion and placement of plant materials and traf- driver and redraw the sight triangle.
fic calming treatments can improve existing
City of Encinitas Neighborhood Traffic Management Program
1 �
streets. They should not be planted in a"clear be needed to improve or maintain after dark
zone."AASHTO defines the clear zone as the visibility of the street and traffic calming
space between a fixed physical object and the treatments. In the "dark" areas of the City,
travelway. The clear zone varies according to additional or extensive use of raised pave-
street function. In residential areas where vehi- ment markers will be required with possibly
cles travel at low speeds, the clear zone is 4 additional signing and high-visibility mark-
feet. In some constrained conditions, the clear ings to highlight traffic calming treatments.
zone is reduced to 1.5 feet. Where parking or
bike lanes are used,the parking lane'or bike Maintenance Issues
lane edge is the edge of the travelway. Trees
can be planted at the edge of the curb and still The introduction-of traffic calming treatments
be within AASHTO guidelines. The visual im- will increase street maintenance. Traffic
pact of street trees is greater when they are calming treatments should be incorporated
planted close to the street. When trees are into existing curb lines when possible to
planted in median areas root barriers are rec- minimize maintenance. The minimum radii
ommended. from curb line to the beginning of a traffic
calming treatment should be 15 feet to permit
Most neighborhood streets have sewer and wa- mechanical street sweeping. Those treatments
ter pipes that need to be protected from tree with a radius less than 15 feet will have to be
roots. Tree roots typically occupy the top swept by hand on a periodic basis.
eighteen inches of soil where they need room
to gather water and nutrients and anchor the In some cases where pedestrian crossings are
tree.For some trees, the extents of the root sys- incorporated within treatments, it will be nec-
tem can be a length that is 1-1/2 times the essary to blow out the pipe under the cross-
height of the tree. If trees are to be planted near walk area.
underground or overhead utility lines,tree type
selection and the use of root barriers or con-
crete jackets around pipes are to be considered. and the channel cleaned where there are no
convenient drainage inlets.
The benefits of trees include increased prop-
erty value,reduction in air pollution, and a re- Ongoing inspection and maintenance of
duction in storm water runoff. (Urban trees in
markings and signs that identify traffic calm-
Vancouver collectively provide 55 million cu- ing treatments is critical for proper operation.
bic feet of stormwater reduction, a benefit val- Traffic calming treatments are to be checked
ued at$331.6 million.) These and other facts as part of the overall sign and marking in-
related to urban trees should be considered spection program.
when construction costs are analyzed. The neighborhood has an opportunity to offer
advice on landscaping as they develop and
Lighting approve their neighborhood traffic manage-
Landscaping may impact street lighting at traf- ment plan. The City maintains landscaping
fic calming treatments. Additional lights may within most traffic calming treatments. If the
City of Encinitas Neighborhood Traffic Management Program
1
landscaped area is less than 100 square feet, 29-30.Roundabouts
the City may require the neighborhood to pro- Roundabouts are circular intersections with
vide maintenance or replace landscaping with channelized approaches. Entering traffic must
concrete. yield to circulating traffic. The design princi-
Where irrigation systems are installed,mainte- ples of roundabouts and the potential trade-
nance requirements will vary with each system. offs are documented in Roundabouts: An In-
Battery operated controllers require battery re- formational Guide,published by the Federal
placement at regular intervals. Other control- Highway Administration (FHWA). The pub-
lers require a power supply and meter. Solar lication acknowledges there is no one optimal
powered irrigation controllers may provide a design, and that simply adhering to the prin-
viable alternative that offers reduced mainte- ciples presented in the guide does not neces-
nance and installation cost. sarily ensure good design. That is responsibil-
ity of the designer.
On major roads,tree canopies should be under-
trimmed to provide 13.5 feet of clear trunk Design speed
height. On neighborhood streets, trees along Although roundabouts can be designed for
the road edges should be under-trimmed to speeds appropriate for traffic calmed areas,
provide 8 feet of clear height. Larger vehicles the designer must recognize that faster driv-
should not be affected by lower neighborhood ers can negotiate roundabouts 5 to 8 mph
street tree canopy heights because larger vehi- over the design speed.Recommended design
cles tend to travel closer to the center of speeds are listed below.
neighborhood streets due to on-street parking.
Under-trimming to arterial road standards re- Roadway Classification Design Speed
duces the visual impact of the trees and may
thereby reduce their effectiveness in any traffic Local 12—15 mph
Collector 15—18 mph
calming treatment.
When pedestrians are likely to use the round-
5.3 Treatment Design about, entry and exit design speeds should be
Because of the wide variety of environments about the same. Careful attention must be
and problems, it is neither feasible nor desir- paid to the deflection for speed control along
able to provide standard templates for each the through leg of the T.
treatment. Section 6 provides a layout for each
treatment with critical dimensions.It is incum- Design Vehicle
bent on the engineer to fully understand the Before designing a roundabout the designer
problem and needs, and to adjust the basic de- needs to confirm the design vehicle for each
sign to meet the situation. To assist in this maneuver. Often a roundabout can be de-
process, comments on each treatment are dis- signed using different design vehicle for dif-
cussed below.Each heading includes the Tool- ferent movements in order to produce the best
box page number for the treatment. overall design. The typical design vehicle for
most roundabouts is a fire utility vehicle or
City of Encinitas Neighborhood Traffic Management Program
11
the ladder truck. On smaller roundabouts it is as close as 15 feet if necessary to avoid drive-
permissible to drive the fire truck over mount- way conflicts. The Manual on Uniform Traf-
able splitter islands. In some locations it is not fic Control Devices (MUTCD)permits cross-
possible to design a roundabout to control ve- walks as narrow as eight feet wide in areas of
hicle speeds and permit buses to make left and relatively low pedestrian volume, which may
right turns. Under this circumstance, a truck also help eliminate driveway conflicts. If nec-
apron that is only 3 inches high with a tapered essary,the driveway can be redesigned and
curb can be used.This is lower than the pre- . extended through the curb extension or bulb
ferred design,but the lower height reduces the out at the roundabout.
impact on bus passengers as the bus rides up
onto the truck apron and down again. If the Roundabouts on Hills
required turning movements cannot be accom- No research yet provides any guidance for
modated, an intersection table, as discussed on roundabouts on a grade. Anecdotal informa-
page 29, could be used instead of a round- tion suggests that a 5 to 6 percent grade might
about. be the upper limit. When designing round-
abouts on hills, there are several items to con-
Splitter Islands sider. First, the grade on the circulating road-
Splitter island curbs can be reduced to four way can vary from—4 percent to 2 percent for
inches to allow the large emergency vehicles to through movements. A positive grade or no
drive over the islands. The Keep Right sign grade can be provided where necessary on the
must also be deleted on mountable splitter is- circulating roadway opposite the splitter is-
lands. This limits the ability of drivers to detect land. The splitter island(s) on any leg that
the splitter island, especially at night. Lighting slopes away from the roundabout must be ex-
is very important. Limited right-of-way may tended so approaching drivers see the island
require the occasional use of painted islands, before they see the roundabout.
rather than raised islands. These islands do not
provide the same physical protection for pedes- Center Island Landscaping
trians the six-inch curbs provide and should be On large roundabouts, a clear zone of 15'
used sparingly. from the edge of the center island to any vis-
ual obstruction is recommended. Trees with
Pedestrian Crossings up to a 4"trunk diameter are recommended
The safest time for a pedestrian to cross the for smaller roundabouts to provide visibility
street in a roundabout is between stopped cars. for drivers entering the roundabout as well as
When a vehicle of average length (10 ft to 16 to provide a visual indication to oncoming
ft) stops at the yield point,the second car typi- drivers that there is an obstruction ahead.
cally stops four feet behind it. The most likely
area for a gap between the stopped cars is be- Manhole Covers
tween 14 and 20 feet, between the first and Manhole covers are often located within inter-
second cars. Locate pedestrian crossings 20 sections and may be in line with the curb lines
feet back from the roundabout entry point,or of a roundabout. When they coincide with the
City of Encinitas Neighborhood Traffic Management Program
1
curb line of the central island or the outside the center is desirable to provide increased
curb line of the central island diameter,the ex- visibility on the small roundabout.
terior diameter can be enlarged or reduced by
one or two feet to fully contain the manhole or 32.Modified Tee Intersection
to totally exclude it from the curb line. On rare
occasions it may be necessary to have the man- There are several techniques for modifying the
hole cover in the curb line,then the curb priority of Tee intersections. The standard
should be shaped to create a"pocket" around treatment is shown in the Toolbox. An alter-
inside of the manhole. nate design is to permit the through movement
farthest from the terminating leg to be a
Signing straight through movement with the reverse
through movement diverted to their right if this
The MUTCD,Part 2, Signing, defines the stan- layout better suits the problem being ad-
dard YIELD sign and standards for placement. dressed.
Note that the use of the yield sign and yield
marking on roundabouts are not mandated, but
that when a YIELD line is used to supplement 33.Intersection Table
a YIELD sign,Part 2 provides Guidance sug- An intersection table allows all movements by
gesting the YIELD line should be located at a all vehicles, an advantage over some round-
point where the road user should yield. The abouts. To ensure vehicles stay within the in-
depiction of these standards and Guidance as tersection area bollards or other barriers must
shown in Figure 3B-26 should not be con- be placed around the right turn radii. The inter-
strued as precise applications of the MUTCD. section table is also widened to encompass the
pedestrian crosswalks so pedestrians do not
Drainage Inlets have to step down and up at the curb lines.
Inlets within a standard intersection must often
be moved because of conflicts with curb 34.Modified Intersection/realignment
ramps. Curb ramps in a roundabout intersec-
tion are typically placed in advance of the right At many intersections streets do not intersect at
turn radius, allowing inlet placement in the 90 degrees, radii are large, streets are offset
center of the right turn radius. from another street and other streets intersect
nearby. The resulting variable angle and large,
Small Roundabouts open expanses of asphalt often create unpre-
dictable or erratic vehicle movements. Redes-
In narrow residential streets,the addition of igning these intersections to more conventional
raised splitter islands to small roundabouts is geometry, in which streets intersect at or close
not always possible. In these cases, the splitter to 90 degrees with smaller radii and have im-
islands can be painted or raised three inches so proved separation between various streets, can
larger vehicle can turn over the island. Keep take many forms. The simplest method is to
Right signs are unnecessary and only one Yield separate each intersection as much as possible,
sign per approach is used in combination with then determine the necessary,standard vehicle
the central island one-way sign.A small tree in
City of Encinitas Neighborhood Traffic Management Program
•
1 �
movements. Any space not required by vehi- 2. Leave the gutter in place between the bulb-
cles for standard movements is converted to out and the existing curb line. Install a
landscape space. To simplify vehicle conflicts, checkered steel plate between the existing
some vehicle movements may need to be curb for the sidewalk and the new curb for
blocked with medians and islands. These types the bulb-out. The bulb out should be de-
of intersection redesigns often create an oppor- signed to invite pedestrians to cross onto
tunity to improve pedestrian crossings by pro- the bulb-out to access curb ramps or cross-
viding curb extensions and short medians. walks at the checkerplate or over the pipe
laid in the gutter. Only checkered plates
35-36.Radii Reduction, Curb Extensions, that are bolted down are to be used to avoid
and Bulb outs creation of tripping hazards. Landscaping
or special treatments should inhibit pedes-
Some intersections have large radii that permit trians from attempting to cross onto the
higher than desirable turning speeds.In these bulb-out at any other location.
cases reducing the turn radii and extending the
curb into the street to create a curb extension Other Considerations:
will shorten the pedestrian crossing distance
and turning speed of vehicles. It is important to ' Vertical curbs are to be used unless mount-
determine the design vehicle requirements able curbs are necessary to accommodate
when selecting radii for either of the above turning trucks and buses.
changes. In some cases the right turn exit radii A transition radius as small as 6 feet is ac-
of a street can be smaller than the entry radii.
ceptable at bulb out connections to existing
According to AASHTO, it is permissible to curbs,but a 15 foot radius is preferred,
require large vehicles to turn across the center- when possible, to facilitate street sweeping.
line of the street they are entering. The larger radius also makes it easier for
Drainage must be addressed because bulb outs drivers to park their vehicles. Combine
can reduce on-street drainage capacity and dis- mid-block bulb-outs and crosswalks when-
rupt gutter flow. On streets with existing curbs ever possible.
and streets where no major drainage improve- Driveways can be accommodated by locat-
ments are planned,there are two options:
ing driveway aprons along the bulb out
1. The existing gutter flow can be adjusted so edges or by shortening the bulb out so it
the water flows along the new curb line. does not encroach on the driveway.
This may require adjusting the length and If a bicycle lane is marked,the bulb out
location of the bulb out to accommodate an
should not encroach into the lane.
existing inlet,moving the existing inlet, or
installing a new inlet on the upstream side
of the bulb out to convey storm runoff to an Signing and Marking
existing inlet. An edge stripe with raised pavement markers
(RPM)is used to define the edge of the travel-
City of Encinitas Neighborhood Traffic Management Program
11
way and/or edge of the street parking. If a bulb- necessary within the diagonal diverter to stop
out diverts two travels lanes into one, striping vehicles driving over the treatment. Trees are
and signing is required in order to channelize useful both as a barrier to errant vehicles and to
vehicles into the inner lane. highlight the treatment from a distance.
37-38. Short Medians at Intersections/ 42. Street Closure
Gateways There are many techniques to close streets,
Short medians at intersections provide a number from a simple barrier to conversion of a whole
of benefits.When designing them it is useful to block to a park or playground. Treatments with
consider that the turning paths of vehicles turn- extensive landscaping can change what can be
ing out of a street is often narrower than the path an unattractive barrier to an aesthetic land-
when making a left or right turn into the street. scaped area. The closure can be extended to the
Therefore, the exit lane can be narrower than the first driveway to maximize landscape area.
entry lane into the street. Typically,the exit lane Bike access and sidewalks through the treat-
can be narrowed to 10 or 11 feet with the entry ment are essential. In rare cases, a driveway
lane being widened to approximately 14 feet. section can be provided through the center of
Use of truck templates is important to confirm the treatment with frangible posts that the
the chosen lane widths. emergency vehicles can break if they abso-
lutely must go through the treatment.
39.Partial Closure
43. Oval Median
The design of these treatments require careful
consideration regarding drainage and street Care needs to be taken with drainage when de-
sweeping. They can have square ends which re- signing these treatments. A low point is created
quire manual sweeping of the gutters or radii at the intersection of the curb and gutter if the
that permit mechanical street sweeping. road is widened into the planter strip. Some-
times it is necessary to install a truck apron on
the central island sides to allow large vehicles
40.Median Barrier to pass through the treatment.
A cut-through should be provided in the median
for pedestrian and bike crossings. Median barri- 44. Chicanes
ers can become useful as pedestrian refuges if
they are six or more feet wide. The most important part of chicane design is to
ensure that the edge of each chicane island
reaches the street centerline.It may be neces-
sary to ban parking within the chicane. Chi-
It is important to ensure pedestrian and bicycle canes are most effective where traffic volumes
access across the diagonal closure. Bicycle ac- are balanced in each direction.Placement of
cess can be provided with simple a cut-through chicanes will depend on site conditions such as
of the diagonal diverter. A barrier is sometimes driveway locations.
City of Encinitas Neighborhood Traffic Management Program
45.Median with Tree Wells is to lay pavers on top of the existing street
These treatments control speed by limiting the surface; the other is a full reconstruction.
space between tree wells and the median. The Landscaping essential to limit the apparent
longer the separation between the trees wells width of the road is very important, as the
and the shorter median,the higher vehicle deflection through the driveway may not be
speeds will be.Trees are very important in large.
these designs to provide good recognition of
the treatments. Signing is minimal with only 48.Angled Slow Points
barrier signs and keep right signs being re- These treatments can be designed in a variety
quired.The median must be wide enough to of ways. Some are useful for on narrow
deflect drivers a substantial distance from their streets and others for use only on wide
travel path. streets. They can also be used in conjunction
with vertical deflection. On wide streets
46.Medians on Curves where a two-lane treatment is to be used, it is
Typically, medians on curves are to be a mini- important to use a raised median in the center
mum of 18 inches wide. In some cases where to stop drivers taking a relatively straight path
this is not possible the use of large pavement through the treatment. On the single lane ver-
markers that are typically 8 to 12 inches wide sion, a speed table may be necessary.
laid at 90 degrees to the travel lane can provide
a substantial barrier to drivers who wish to cut 49-50. Speeds Humps and Speed Tables
across the centerline of the street. It is impor- It is important to ensure that ramps and treat-
tant to provide openings in the medians at ment height is not too low or ramp tapers too
driveways. In some cases, the openings may be long. If the rate of change in vertical position
spaced such that the median will have to be is too forgiving drivers will be able to go over
extended around the curve and along the these treatments at a fast rate of speed. The
straight section of the road to provide reason- ends of speed humps and speed tables are an-
able visibility of the median. other critical part of the design. When the
ends are designed in a forgiving, easy taper,
47.Driveway Link drivers can put one set of wheels in the gutter
This treatment is designed to create the illusion and go over the speed hump at high speeds,
that the street has been closed and a park has sometimes in excess of 40 mph. Vertical curb
been created. Construction of the treatment in- to deter this behavior is preferred.
cludes a driveway through the treatment that
links both sides of the street . The driveway 51. Short medians
link is a similar to a typical driveway in that it This treatment is appropriate for wide streets
rises above the existing road level,becoming a to reduce travel lane width,provide pedestri-
very long speed table. Two options have been ans with crossing refuge areas and to prevent
used to construct these treatments. One option drivers from passing other vehicles.A series
City of Encinitas Neighborhood Traffic Management Program
of medians varying in length are located be- 54.Street Narrowing
tween driveways. Space between the medians
is slightly wider than the driveway to allow Addition of curb and gutter can physically and
visually narrow a street, especially if the curb
motorists room to turn into and out of their
driveways.A simple design technique is to lo- and gutter is brought in from the existing edge
cate each driveway,project it to the center of of pavement. The curb and gutter will improve
the road, and widen the projection by 3 to 5 drainage, stop damage to the planter strip, and
feet. The space not required for driveways be- force drivers to park on the road pavement in-
comes a median. Medians do not deflect vehi- stead of the planter strip or sidewalks. During
cles, so it is important to minimize the lane the design of this treatment, it is useful to con-
width to allow a high level of landscaping to sider the addition of other traffic claming treat-
visually narrow the street. The City of Encini- ments and curb extensions to help protect park-
tas does not landscape medians less then five
ing spaces.
feet wide.
55. Centerlines
52.Raised Pedestrian Refuge Centerlines create certainty. They provide driv-
ers is a short median provided as a refuge is- with clear information regarding placement
land for pedestrians crossing the road. It should and offset of approaching vehicles. This allows
drivers to proceed with certainty and be com-
have at least 20 feet of raised island on either
side of the crosswalk to give pedestrians a fortable traveling at higher speeds. The loss of
sense,of security. These refuges can be supple-
certainty when the centerline is removed helps
mented with curb extensions to shorten cross- to slow drivers,particularly on short streets.
ing distance. The cut-through in the refuge can
be perpendicular to the cross walk or angled at 56.Bike Lanes
45 degrees to encourage pedestrians to look for Bike lanes designate travel space for bicyclists,
approaching vehicles. which increases rider comfort and the predict-
ability of bicyclist movements. This added
53.Woonerf travel space also makes it feasible for motorists
This treatment is better used as part of new to encroach into the space designated for bicy-
street construction or the reconstruction of an clists and travel faster through or around traffic
existing short street. The intent is to provide a
calming treatments. Limiting bike lanes to
very low speed vehicle environment by using a
streets with more than 1,500 vehicles per day
single 10 or 11 foot lane that can be used by prevents this adverse impact in residential ar-
service and emergency vehicles,but which dis- eas. There are generally few conflicts between
courages high speed by vehicles. There are bicyclists and vehicles in low-speed, low-
many design techniques available for this treat-
volume residential areas.
ment. Parking can be provided between curb In places where bike lanes are provided the
extensions. designer must be aware that motorists will
City of Encinitas Neighborhood Traffic Management Program
drive over painted lines and adjust the design ac-
cordingly. One technique is to move curb exten-
sions or islands between the bike lanes and the
treatment. Care must be taken to ensure the design
does not set up potential conflicts between pedestri-
ans and bicyclists.
57. On Street Parking
On street parking should be encouraged on all resi-
dential streets. Parked vehicles can narrow the
street to a single lane, forcing drivers to pull into
driveways or empty spaces between parked vehi-
cles to let an opposing vehicle pass. This reduces
the speed of both vehicles.
City of Encinitas Neighborhood Traffic Management Program
6.0 Traffic Calming Treatment Design Guidelines
Traffic calming, or the management of traf-
fic within neighborhoods,was originally de- eluded in section 5.0,Design Considerations.
veloped in Holland and Australia in the early It will be necessary for lighting to be
1970's. Although its use is increasing checked, drainage adjusted or a treatment de-
throughout the U.S., there are no national de- signed so that it has little to no impact on
sign standards for the design of these treat- drainage. Landscaping is an important ele-
ments or for how to sign and mark them. The ment of each horizontal deflection treatment
design guidelines that follow are a collection and where possible landscape materials
of traffic calming treatments based on the lat- should be provided where feasible to enhance
est information using standard engineering both the visibility and appearance of each
design techniques and philosophies.Where treatment.
possible, signs and markings from the
MUTCD are shown in the guidelines.Where When designing each treatment it is neces-
necessary, enhancements have been added. sary to confirm the design vehicle/s, each
movement for design vehicle/s. Often differ
Some of these treatments are based on Design ent design vehicles can be specified for dif-
ferent,movements. Appropriate design speeds
most identical neighborhood environment as should be selected and the speed curves in-
the U.S. Other treatments are commonly eluded within these guidelines used to design
used in the U.S. each treatment.
Since there is no optimum design for treat-
ments or any consistency in the environment
in which they are to be used,these guidelines
are intended to serve only as a guide to indi-
cate the basic geometry and sign layout for
each treatment. The design engineer can use
the basic layout and underlying philosophy to
help them design each treatment to suit each
location in relationship with adjacent treat-
ments.
These layouts do not go into detail about
drainage,utilities, lighting or landscaping.
These items are specific to each situation and
vary considerably. More information about
the impacts of these and other items is in-
City of Encinitas Neighborhood Traffic Management Program
Figure 4. Cross Reference Guide
E11000010
Roundabout 29-30 65-67 D-1
Traffic Calming Circle 31 D-2
Modified Tee Intersection 32 67 D-3
Intersection Table 33 67 D-4
Modified Intersection/Realignment 34 67 D-5
Curb Radius Reduction 35 68 D-6
Curb Extensions/Bulb Outs 36 68 D-6
Short Median at Intersection 37 69 D-7
Gateway Treatment 38 69 D-8
Partial Closure 39 69 D-9,10
Median Barrier 40 69 D-11
Diagonal Closure 41 69 D-12
Street Closure 42 69 D-13
Oval Median 43 69 D-14
Chicane 44 69 D-15
Median with Tree Wells 45 70 D-16
Median on Curve 46 70 D-17
Driveway Link 47 70 D-18
Angled Slow Points 48 70 D-19,20,21
Speed Hump 49 70 D-22
Speed Table 50 70 D-23
Short Medians 51 70 D-24
Raised Pedestrian Refuge 52 71 D-25
Woonerf 53 71
Narrow Street: Add Curbs 54 71
Centerlines 55 71
Bike Lanes 56 71
.On-street Parking 57 72
City of Encinitas Neighborhood Traffic Management Program
Minimum width of splitter
island varies depending on the
street hierarchy from 111 on
narrow local streets to 8 ft for
W 11 -2 -,
R4-7 all other roundabouts
Curb return pedestrian ramps
are preferred because they
provide better guidance to
visually impaired people.
IA-2
RI-2
Rl-
W 11 A-2
W 11A-2
0
R4-7 37.5 ;.s?�p'. . R4-7 N
18.0
0
W11A-
W1 1A-2
1-2
8to10ft.
W1 1A- R 2
0
4. N
8180.0
Roundabouts vary in size.This is
a small roundabout that typifies
o residential street roundabouts
Sign Descriptions 114-7 ri where SU vehicles could proceed
RI-2 Yield 1 -2 through and make right turns but
not left turns.Larger vehicles
W 1-8 Chevron could proceed through but not
W I Pedestrian Crossing turn left or right unless they
R4-7 7 Keep Right tamed over the islands.At
smaller roundabouts the concrete
splitter lands can be replaced
with painted islands.
28.0
All dimensions in feet unless otherwise noted. NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES ROUNDABOUT
FIGURE D-I
_2
T ,
Circulating width varies 15 to 20 1-2
WA-8(four)
Y A A
3
Ir
o :
RI-2r ` Circle Diameter
Sign Descriptions
R1-2 Yield
WI-8 Chevron Road Width
Traffic calming circles are only intended for Approximate Dimensions of Traffic Circle
use on narrow streets.Roundabouts should for Varying Roadway Widths
be used at larger intersections.
Roadway Width Curb Return Radius Ci cle Diameter
Pedestrian crossings should be located out of
the path of the circulating vehicles.
20 20 11
25 12
24 12 13
Varies 4.0 min. 15 14
20 15
6"Curb
Landscaping
2%min slope These are approximate dimensions intended as a
guide to the feasibility of using a traffic calming
3"Min. circle.They are not a substitute for an engineering
SCCtion 1'�1'1 design using vehicle templates and speed curves.
All dimensions in feet unless otherwise noted. NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES TRAFFIC CIRCLE
FIGURE D-2
rf 1.5
R4-7 �� O
20.7 R4-7
11.0 Min. R4-7 R 7
11.0 Min.
2.0
R4-7
11A 11.0
RI-1
R4-7
24.0
Sign Descriptions
R1-1 Stop Sign
R4-7 Keep Right
W1-8 Chevron
All dimensions in feet unless otherwise noted.
NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES MODIFIED TEE INTERSECTION
FIGURE D-3
RI-1 Bollards
Minimum I%slope
required in all areas
for drainage
Optional crosswalk lines
Ifff
o ,o.
00
'i' •
W17-1
- W13-1
-:a- 100 from
intersection
A :... 8.0 A
S.,
0
W17-1 Truncated •
W13-1 domes
100 from Optional crosswalk
intersection lines
Rl-1
If intersection is controlled
by Stop signs,W8-17 Center of roadway
signs are not needed on the Center of travel lane
Stop sign approaches.
Sign Descriptions: 1-ft gap
W17-1 Speed Hump 1-ft white
W13-1 Advisory Speed markings 10
Rl-1 Stop
10.0 4 to 5 inches
Ramp Section AA
All dimensions in feet unless otherwise noted. NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES INTERSECTION TABLE
FIGURE D-4
............
..........
.............=.
Median added r
Curbs extended to reduce
asphalt and realigncurves
Intersection redesigns can take many forms. This is just one
example. Typical techniques include reducing corner radii,
realigning streets to as near as possible to 90 degrees, adding
medians,moving streets that are offset to the primary intersection
away from the primary intersection,adding bulb outs,etc.
All dimensions in feet unless otherwise noted. NOT TO SCALE
k_
DEPARTMENT OF
ENGINEERING SERVICES MODIFIED INTERSECTION/REALIGNMENT
FIGURE D-5
Previous radius /
Curb Radius reduction \
R14
l
24.0 MIN.
RI-1
�r
Radius is variable can
vary from 15 to 30 4 Parking
depending on design °O Lane
` vehicle.
Straight section
\ is variable.It
\ can vary from
\ 0.0 to 10+feet.
Curb radius reduction
/ with bulb outs
� I
Sign Description:
R1-1 Stop
Curb radii reductions must be designed to
match design vehicle turning paths,
especially at intersections where emergency
vehicles turn frequently.Large vehicles are
permitted to drive over the center line of the
street they are to enter.
All dimensions in feet unless otherwise noted. NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES CURB RADIUS REDUCTION, CURB EXTENSIONS
FIGURE 0-6
Local Street
or collector
I
1
1 RI-1
\
�` R4-7 Double yellow
R4-7 20 to 50 feet 10.0 desirable R4-7 center line
5.0 in. �
/oon ii based 14.0 desirable Local Street
R4-7 \ of esgn ve hicle.
1
1
On very wide streets it may be neessary to add bulb outs
to protect on street parking and narrow the median.
Parking is prohibited next to median.
The maximum length of the median islands is affected
Sign Descriptions by driveways.
R4-7 Keep Right
RI-1 Stop
All dimensions in feet unless otherwise noted. NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES SHORT INTERSECTION MEDIAN
FIGURE D-7
Median offset and taper is set
according to standard for the
approach design speed.
Local Street
R4-7
10.0 desirable
Double yellow center line
R4-7
14.0 desirable
A median with changes in pavement provide a change in
the entry environment of a street.
Pavement changes can consist of brick paving,colored
asphalt,colored concrete or a textured pavement.
The maximum length of the median islands is affected
by driveways.
Parking is not permitted next to median.
Sign Descriptions
R4-7 Keep Right
Rl-1 Stop
All dimensions in feet unless otherwise noted. NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES GATEWAY TREATMENT
FIGURE D-8
W14-2
T
Exit only directional closure that
removes exiting curb and gutter and
provides an unified design.
i
Original Curb `:::::
.............
Offset allows
5.5 bicyclists to travel
along the street
o �
_1:::: Exit only directional closure that adds
;.:, __• an island separate from exiting curb
and gutter and provides an add-on
appearance.
Width depends on design vehicle
W14-2 Required at entry to street
to discourage drivers from entering
and having to turn around.
Sign Descriptions
W14-2 No Outlet
RS-1 Do Not Enter
All dimensions in feet unless otherwise noted. NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES PARTIAL CLOSURE (ENTRANCE ONLY)
FIGURE D-9
Exit only closure that removes exiting
curb and gutter and provides an
unified design.
Rl-1 :. ginal Curb
X.
:a
-' -1
R3-2
gS•
Offset allows
bicyclists to travel
along the street
5.5
R3-2 4 RI-5
\ 5.0 glo
RI-5 JL
: 1 l-
i
Exit only closure that adds an island
separate from exiting curb and gutter
and provides an add-on appearance.
Sign Descriptions
W14-2 No Outlet
R5-1 Do Not Enter
R3-1 No Right Turn
R3.2 No Left Turn
All dimensions in feet unless otherwise noted. NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES PARTIAL CLOSURE (EXIT ONLY)
FIGURE D-10
,Rl-1
R3-5 s
='I Median offset and taper is set
according to standard for the
approach design speed.
C
o
R4-7 6. m R4-7
in. r`i
HDoubleyellow 5.0 20 to 30(typ.)
cener ne Minimum opening for R6-1
pedestrians and bicyclists.
Crosswalks are optional.
Z
i;Rl-1
R3-5
Parking is not permitted next to median
Sign Descriptions
R4-7 Keep Right
R6-1 One-way
RI-1 Stop
R3-5 Right Turn Only
All dimensions in feet unless otherwise noted. NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES MEDIAN BARRIER
FIGURE D-11
-W ; R3-5R
R3-5L
Bicycle path openings
WI-8 _ Bollards at 5-feet
-'-! typical spacing
R1.0
W1-8
.: 2Q
i!.
R3-5L
R3-5R -�
riginal Curb
Parking prohibition signs may be needed.
Depending on pedestrian demand or other
local conditions, a sidewalk along the
Sign Descriptions
WI-8 Chevron center of the divertor.
R3 5R Right Turn Only Landscaping is to be raised to create a
R3-5L Left Turn Only barrier or bollards are to be added.
All dimensions in feet unless otherwise noted. NOT TO SCALE
1..
DEPARTMENT OF
ENEUSEMEMOVEEMO BES DIAGONAL DIVERTER
FIGURE D-IZ
R3-5
Tip
Depth of closure is dependent on funds,
driveways,ultimate use of excess area.It can
encompass the minimum area shown or a whole
block.
..
lr7l-
Wl-8
W14-2 Required
at entry to block
Sign Descriptions
WI-8 Chevron
R3-5 Stop
W14-2 No Exit
All dimensions in feet unless otherwise noted. NOT TO SCALE
-a=
Y-
DEPARTMENT OF
ENGINEERING SERVICES STREET CLOSURE
FIGURE D-13
40.4
Design speed, 20 mph,
Design Vehicles,SU
---��°-----
—WI-8
o _J—
c Truck Apron for Single Unit Truck R4-7
N Truck Apron for WB-50 Double yellow
center line
— •--yy+••�, . —
.'.•.9.'.'.'.•.'.• N
WI-8 R4-
4 .0
44.5
Design speed, 23 mph,
Design Vehicles,WB-50
Can be designed at different speeds,on
Sign Descriptions different widths of street,for different
types of vehicles.Two samples are shown
R4-7 Keep Right above.A lower speed,smaller vehicle on
WI-8 Chevron top with a higher design speed and larger
vehicle on the bottom.
Parking is not permitted next to median.
6.0" Section AA
3.0" 3.0"
Landscaping
Truck Apron for WB-50
Truck Apron for Single Unit Truck
All dimensions in feet unless otherwise noted. NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES OVAL MEDIAN
FIGURE D-14
W--IWl-5 and W13-1,(15 mph)
250'in advance of chicane
24.0
1.5 gutt er
W 1_g I There are many design options for chicanes.The
back-to- shape of the islands can vary from the semicircle
back I shown to square to a semicircular design with
approach tapers.
Varies I This design is for a 24.0'wide street,using a Single
according Unit truck as the design vehicle.The design speed is
to street
width approximately 20 mph.
Each design should be prepared using truck turning
templates or AutoTurn and speed curves.
U
w I Travel path through chicane is a single lane.
Spacing of chicane is dependent on driveway
spacing,street widths,and design speed.
0
I Landscaping in the chicane islands should not
v obscure approaching driver's vision of oncoming
vehicles.
IWl-8
a,
back-to-
Iback
C)
3 Sign Descriptions
W13-1 Advisory Speed
WI-8 Chevron
v
WI-5 Horizontal Alignment
1
Wl-8
back-to-
back
WI-5 and W13-1,(15 mph)250'in
advance of chicane
All dimensions in feet unless otherwise noted. NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES CHICANE
FIGURE 0-I5
Width varies depending on driveway spacing
20.0 to 50.0 ft typical 50.0 8.0
Tree well with tree.
7
1.5 gutter vari ble
Parking Lane °p
Double yellow WI-8 WI-8
center line
o
W I-8 W l-8
R4-7 R4-7
Parking Lane 11 to 12 ft.T ical d
Gutter may or may not be
Driveways can be included included depending street
within treatment with due care width.
of vehicle turning paths.
Varies 4.0 min.
Landscaping 2%minimum
slope
Y Min. Rh
Section AA
Sign Descriptions
R4-7 Keep Right
Wl-8 Chevron
All dimensions in feet unless otherwise noted.
NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES SHORT MEDIAN WITH TREE WELLS
FIGURE 0-I6
Taper length is dependent on the width of the
median and the approach speed.A taper of 1
in 15 is recommended. Optional 8"yellow
edge lines to help
define the median when
there are many breaks
for driveways.
R4-7
Typical median width varies
from 1:5 to 6 feet.However its
width is dependent on the width
of the road,the need for
parking around the curve,and R4-7
design vehicle.
The median can be landscaped,
brick paved or concrete.
Where driveways exist provide an
opening within the median.the opening
is dependent on the needs of the design
vehicle.
Sign Descriptions
R4-7 Keep Right
All dimensions in feet unless otherwise noted. NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES MEDIAN ON CURVE
FIGURE 0-17
Length dependant on situation
Typical 60 to 100 feet
Driveway 1.5 gutter
:•:1 :?-)
-WI-8+Yield
.. to oncoming
: ::.
-:: traffic
1
1_.__ .1 0
Wl-8+Yield -- W1-8+Yield
to oncoming
r
............
- . ...............: to oncoming
traffic traffic
Driveway
There are many design options for a
Driveway Link.The basic design is to
close the street and provide a 10-ft wide
driveway through the area.The driveway
can be curved,it can be angled or bent as
shown.Landscaping is fairly dense to
create an appearance of a closed road.
Sign Descriptions The driveway is typically raised with
Extra Yield to Oncoming traffic driveway ramps at each end.
WI-8 Chevron
Driveways to abutting properties can
access this driveway link.
All dimensions in feet unless otherwise noted.
10 NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES DRIVEWAY LINK
FIGURE D-18
121 1.5 gutter
w� p 8'white edge line
R4-7 R4-7
0
8'yellow line
20-30°
22.8
Sign Descriptions
R4-7 Keep Right
W1-8 Chevron
All dimensions in feet unless otherwise noted.
NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES TWO LANE ANGLED SLOW POINT WITH MEDIAN
FIGURE D-19
Islands are to be landscaped to help reduce
road width and to crate a more effective W5-1
barrier W13-1 150 feet
from Slow Point
1.5 gutt er
ti~
:te:Wl_g::.:;j.:: 8 inch white edge line
-8'
Extra Extra sign-Yield to �� 2� Extra sign-Yield to
oncoming traffic 0 oncoming traffic
8 inch white edge line 10-30° WI-8
W5-1
W13-1 150 feet
from low Point
Sign Descriptions
W5-1 Road Narrows
W1-8 Chevron
W13-1 15 mph speed plate
Extra Yield to Oncoming vehicles
All dimensions in feet unless otherwise noted.
NOT TO SCALE
10
DEPARTMENT OF
ENGINEERING SERVICES ONE LANE ANGLED SLOW POINT
FIGURE 0-20
W5-1
W13-1 150 feet
from Slow Point
q' Wl-8 1.5 gutter
.•yZ.W _ Extra sign-Yield to
0 oncoming traffi
,moo•
8 inch white edge line s 9 8 inch white edge line
•0
Extra sign-Yield to .W l-g 1*6-30°
oncoming traffic ''.'.'..
-W1-8
W5-1
W13-1 150
feet from
Slow Point
5.0 12.0 5.0
7—fZ,F
4 inches
Section AA.
Sign Descriptions
W5-1 Road Narrows
W1-8 Chevron
W13-1 15 mph speed plate
Extra Yield to Oncoming vehicles
All dimensions in feet unless otherwise noted.
NOT TO SCALE
is
DEPARTMENT OF
ENGINEERING SERVICES ONE LANE ANGLED SLOW POINT WITH SPEED TABLE
FIGURE D-21
ca
W17-1
W13-1
100 ft from
12.0 crossing
W17-1
W13-1 A A
100 ft from
crossing
OM
Center of roadway
Sign Descriptions:
Center of travel lane W17-1 Speed Hump
W13-1 Advisory Speed
0
1-ft gap
1-ft white
markings 5.0
0.0 0.64 1.22 1.75 2.22 2.64 3.00 3.31 336 3.75 3.69 3.91 4.00
]-LiLi
6.0
12.0
Section AA
Watts Profile h curb to support speed
hump and to stop drivers
Sidewalk putting two wheels in gutter
to go over speed hump faster.
Existing road surface
Section BB
All dimensions in feet unless otherwise noted. NOT TO SCALE
-.4
DEPARTMENT OF
ENGINEERING SERVICES SPEED HUMP
FIGURE D-22
W1lA-2 W11A-3
W13-1
5.9 1 20 5.0
WllA-3
W13-1
If the speed table is not to be combined
with a pedestrian crossing then the crossing
Center of roadway signs and tactile surfaces can be deleted.
Center of travel lane Drainage inlets are required on the uphill
side of the raised crosswalks unless bolted
down covers are provided between
crosswalk and curb.Curb extensions can be
1-ft gap added to narrow travel lanes and shorten
1-ft white pedestrian crossing distance.
markings 5.0
4 inches
5.0 12.0 5.0 Sidewalk Crosswalk
4 inches Existing road surface
Section BB with Crosswalk
Section AA-
Sidewalk inches
Sidewalk Crosswalk 6"curb
Sign Descriptions:
W1 IA-2 Pedestrian Crossing
W1 IA-3 Raised Pedestrian Crossing Existing road surface
W13-1 Advisory Speed Plate Section BB when used as a speed table only
All dimensions in feet unless otherwise noted. NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES SPEED TABLE
FIGURE D-23
Driveway
Drivewa
4 inch yellow edge line
N
R4-7
16.0 minimum a x +`
Driveway
This treatment is a continuous median with openings opposite driveways.
Each side of each driveway is projected to the center of the street and a
minimum 16.0'foot wide opening is created opposite the driveways.
Where the openings overlap the median opening increases in length.
Where the openings do not overlap a short median is created.
The width of the median depends upon the street width and the need to
provide on street parking.
Sign Descriptions
R4-7 Keep Right
Only used at the start of the medians.
All dimensions in feet unless otherwise noted. NOT TO SCALE
a—
DEPARTMENT OF
ENGINEERING SERVICES SHORT MEDIANS
FIGURE D-24
On wide streets it may be desirable to
add bulb outs to narrow the travel lane
rather than provide a very wide
median.
Width of bulbout depends on
- - --
width of street
R4-7 ° 8.0 R4-7
X
R
15.0 to 20.0 Local Street
or collector
Min.6.0
NV110 �.
Median approach taper as per 2.0 tactile strip
standard design for the particular 12 inch white line or ladder styple
design speed of that approach. markings
On very wide streets it may be necessary to add bulb outs
to protect on street parking and narrow the median.
The maximum length of the median islands is affected
Sign Descriptions by driveways.
R4-7 Keep Right No parking signs may be required opposite the median
Wl1-2 Pedestrian Crossing islands
All dimensions in feet unless otherwise noted.
NOT TO SCALE
DEPARTMENT OF
ENGINEERING SERVICES RAISED PEDESTRIAN REFUGE
FIGURE 0-25
Appendi*x
City of Encinitas Neighborhood Traffic Management Program
r
ENDNOTES
1 Roundabouts: An Informational Guide U.S. Department of Transportation,Federal Highway
Administration.Page 20, Item 2.1.7. The service life of a roundabout is approximately 25
years, compared with 10 years for a typical signal
2. Roundabouts: An Informational Guide U.S. Department of Transportation,Federal Highway
Administration. Page 34, Item 2.2.5. This section discusses the need to compare emergency
vehicle delay at a roundabout with that of alternative traffic control measures.The discussion
points out that emergency vehicles benefit from the lower vehicle speeds and the elimination
of the vehicles that can travel at high speeds through to intersection and collide with their ve-
hicle.
3. Designing Sidewalks and Trails for Access, Best Practices Guide,FHWA, 2001. Chapter 9,
Traffic Calming. This publication acknowledges the universal benefits of traffic calming and
cites specific examples of potential negative impacts.
4. The Manual on Uniform Traffic Control Devices (MUTCD)is approved by-the Federal High-
way Administrator as the National Standard in accordance with Title 23 U.S. Code, Sections
109(d), 114(a), 217, 315, and 402(a), 23 CFR 655, and 49 CFR 1.48(b)(8), 1.48(b)(33), and
1.48(c)(2). Available online at http://mutcd.fhwa.dot.gov
ADDITIONAL RESOURCES
Managing Speed: Review of Current Practice for Setting and Enforcing Speed Limits;Transpor-
tation Research Board,National Research Council Special Report 254, 1998.
A Policy on Geometric Design of Highways and Streets, 1994. American Association of State
Highway and Transportation Officials.
Traffic Calming: State of the Practice; Institute of Transportation Engineers for the Federal High-
way Administration,August 1999.
City of Encinitas Neighborhood Traffic Management Program