Pedestrians

Traffic Calming Design Guidelines

The term "traffic calming" is applied to design interventions that make streets safer by reducing opportunities for illegal speeding and aggressive driving. These measures can also enhance pedestrian comfort and flow. Measures may include the installation of traffic calming devices such as speed bumps, curb extensions, raised crosswalks, as well as other interventions. The Street Design Manual is a comprehensive resource for in-depth information on DOT's traffic calming toolkit. Another helpful resource is the School Safety Engineering Project General Mitigation Measures Final Report.

Traffic calming devices are part of a toolbox of measures DOT uses to enhance safety, along with engineering and signal timing changes, and education and enforcement initiatives. Community groups, elected officials and Community Boards can report conditions (e.g. speeding) to the appropriate DOT Borough Commissioner for analysis and consideration for traffic calming interventions or other safety measures.

DOT has taken unprecedented steps to focus its safety engineering efforts in areas around schools and seniors, including the use of traffic calming devices. DOT's safety programs include:

Safe Routes to Schools

This program focuses safety enhancements at city schools with the highest accident rates. DOT examined accident histories around the city's 1,471 elementary and middle schools and established two groups of 135 priority schools (270 schools total) to be studied for traffic safety improvements. The studies and short-term improvements were completed at the first group of 135 schools in 2007 and capital improvements are underway. The second group of 135 schools is currently under study. In addition to these improvements, DOT upgraded school crosswalk signs around all 1,471 school locations and created and distributed traffic safety maps for each school. Learn more about Safe Routes to Schools

Safe Streets for Seniors

This program is a major pedestrian safety initiative for older New Yorkers. DOT evaluates pedestrian conditions from a senior's perspective to implement safety engineering changes in 25 neighborhoods citywide that have both a high density of senior residents and a high number of senior pedestrian fatalities and severe injuries. Learn more about Safe Streets for Seniors

Traffic Calming Devices

Below is a list of traffic calming devices used by DOT, which includes the benefits, considerations, appropriate conditions for installation and design guidelines for each device. Any of these devices may be considered as part of DOT's school and senior safety programs. With the exception of the guidelines for raised speed reducer, which includes specific criteria for streets adjacent to schools, the guidelines for the approval and installation are the same on all city streets. However, DOT continues, through Safe Routes to School and Safe Streets for Seniors initiatives, to focus its efforts on these areas. The guidelines below are not a replacement for thorough investigation and engineering.

Raised Speed Reducers

A raised speed reducer is a raised area of a roadway that deflects both the wheels and frame of a traversing vehicle with the purpose of reducing vehicle speeds. This treatment is widely used.

The two basic types of raised speed reducers are speed bumps and speed tables. Both are typically raised 3 to 4 inches above the level of the roadway, and both have a proven speed-reducing track record in New York City. While a speed bump is relatively shorter in length (i.e., up to 20 feet long), a speed table is longer (i.e., 22 to 30 feet long), with a flat section in the middle, sometimes including a raised pedestrian crossing.

Benefits

  • Compels drivers to travel at speeds no higher than the street's design speed
  • A speed table can be used to provide a raised mid-block crossing in conjunction with a stop control

Considerations

  • Impacts emergency vehicle movement
  • Snow plows must be given advance warning
  • May generate additional noise

Appropriate Conditions for Installation

  • Can be requested by a Community Board or other community group, elected officials or individual citizens, with approval based on a DOT field study of the location using speed survey, geometric, and street operations criteria. Requests can be made by emailing the Commissioner or writing a letter to the Commissioner, Department of Transportation, 55 Water Street, New York, NY 10041.
  • A field review is conducted to determine feasibility of a raised speed reducer based on the following criteria:
    • On streets immediately adjacent to Priority Schools, speeding is not a criteria for feasibility and a speed study is not required
    • On streets immediately adjacent to non-Priority schools the 85th percentile speed shall be equal to or greater than 25 mph
    • On all other streets the 85th percentile speed shall be equal to or greater than 30 mph
    • Street shall not be designated as a Local or Through truck route
    • Street shall not be on an MTA bus route or tour bus route or route of any other bus operator
    • Street shall not be on an emergency vehicle route or snow emergency route
    • Street shall not have a Fire Department house or hospital emergency entrance located on the block
    • Can be either one-way or two-way but should have only one moving lane in each direction
    • If street width is greater than 45 ft, then lanes should be clearly marked to establish that there is unambiguously one moving lane in each permitted direction
    • No speed reducer shall be installed at a critical point in a roadway system (e.g., at a severe horizontal, or vertical curvature) or on streets with more than an 8% grade
  • Placement of a raised speed reducer shall be at least:
    • 5 ft from any driveway or curb cut on a local street (additional clearance may be required for curb cuts utilized by trucks)
    • 15 ft clearance from either side of a hydrant
    • 200 ft from an intersection that is controlled by a stop sign or signal
    • 100 ft from an uncontrolled intersection
    • 200 ft from a curve in the roadway
    • 250 ft minimum spacing between reducers
    • 2 ft from a manhole or utility cover on approach or 6 ft after the reducer
  • The location can be investigated by DOT for a "reduced school speed zone" if a speed reducer is not feasible but the street has an 85th percentile speed of 25 mph or higher and is immediately adjacent to a school. If the location is immediately adjacent to a Priority School, the location can be investigated for a "reduced school speed zone" regardless of the presence of speeding.
  • Final installation of a raised speed reducer will require Community Board approval, except for those located adjacent to schools.

Design Guidelines

  • Speed reducers may be either 3" high (on local streets without a school) or 4" high (near school locations only)
  • Space raised speed reducers to maintain desired operating speeds
  • Appropriate warning signs and roadway markings should accompany raised speed reducers
  • Locate raised speed reducers in the middle of the roadway, with the gutters kept clear for proper road drainage
  • Use signage or other methods to alert operators of snow-clearing vehicles to the presence of raised speed reducers
  • While raised speed reducers are an effective method to retrofit existing streets to reduce motor vehicle speeds in lieu of street reconstruction, all newly reconstructed streets should be comprehensively designed to achieve desired speeds, e.g., using appropriate roadway width and alignment, horizontal deflection, traffic controls, trees, and other traffic calming treatments

Lane Narrowing and Lane Removal

A lane narrowing removes excess width from existing moving/traffic lanes without changing the number of lanes. A lane removal reassigns underused traffic lanes to other functions. This treatment is widely used.

These design techniques, while not traffic calming devices, have powerful traffic calming benefits. Both may be accomplished by adding turning lanes, pedestrian refuge islands, expanded pedestrian space, on-street or separated bicycle lanes, parking or other functions.

Benefits

  • Reduce opportunities for speeding and aggressive driving, reducing the severity and frequency of crashes
  • Organize the roadway to provide clearer instruction to drivers, cyclists, and pedestrians
  • Provide space for pedestrian refuge islands, assigned turn lanes, angle parking, wide parking lanes, bus lanes, bicycle lanes, expanded sidewalks/pedestrian space, or other uses

Considerations

  • Traffic conditions must be considered in planning lane removals; detailed analysis may be needed
  • Commercial loading and other uses should be considered in planning lane narrowing
  • Planned uses, such as bus lanes or bicycle lanes, should be taken into consideration
  • Effects of narrowings on turning movements should be tested

Appropriate Conditions for Installation

  • Consider lane narrowings on corridors with excessively wide lanes
  • Multi-lane corridors with excess capacity (more traffic capacity than traffic volume) are excellent candidates for lane removal
  • Multi-lane corridors may be good candidates for lane removal in concert with other treatments, such as signal timing changes
  • Lane narrowing and removal should be prioritized on corridors with safety or speeding concerns, or where prioritization of non-general traffic is desirable

Design Guidelines

  • Lane narrowings and removals should result in standard-width lanes
  • When other treatments are included in a lane narrowing/removal, see specific guidelines for those treatments

Curb Extensions

An expansion of the curb line into the lane of the roadway adjacent to the curb (typically a parking lane) for a portion of a block either at a corner or mid-block. This treatment is widely used.

Also known as neckdowns, curb extensions can enhance pedestrian safety by reducing crossing distances, can relieve sidewalk crowding, and can provide space for functional elements such as seating, plantings, and furniture. In addition, two curb extensions can be located on either side of a street to create a mid-block narrowing or at an intersection to create a gateway.

Benefits

  • Calms traffic by physically and visually narrowing the roadway
  • At a corner, slows turning vehicles and emphasizes the right of way of crossing pedestrians
  • Shortens crossing distance, reducing pedestrian exposure and minimum required signal time for crossing
  • Improves the ability of crossing pedestrians and drivers to see each other
  • Makes the crosswalk more apparent to drivers, encouraging them to stop in advance of the crosswalk and reducing illegal parking within crosswalk
  • Reinforces lane discipline through intersection, preventing vehicle passing maneuvers in parking lane
  • Provides additional pedestrian space and reduces crowding, particularly for queuing at crossings and bus stops or when located at a subway entrance or other protrusion
  • Creates space that may be used to locate street furniture, bike parking, bus stop, public seating, street vendors, etc., potentially reducing sidewalk clutter
  • Keeps fire hydrant zone clear when located in front of a hydrant
  • Defines the ends of angle parking
  • Can discourage truck turns onto streets with no truck regulations

Considerations

  • May impact street drainage or require catch basin relocation
  • May impact underground utilities
  • May require loss of curbside parking
  • May complicate delivery access and garbage removal
  • May impact snow plows and street sweepers

Appropriate Conditions for Installation

  • Only applicable within a curbside parking lane
  • Corners with marked pedestrian crosswalks in retail districts, directly adjacent to schools, at intersections with demonstrated pedestrian safety issues, on wide streets, or in areas of high foot traffic
  • At school crosswalks
  • At mid-block crossings
  • Intersections where a two-way road transitions to oncoming one-way operation so as to block wrong-way traffic from proceeding straight onto the one-way portion (a "blockbuster")
  • Next to subway entrances or other sidewalk pinch points so as to increase pedestrian walking or queuing space
  • In front of fire hydrants so as to keep clear of parked vehicles
  • Consider at all corners and pedestrian crossings
  • Consider elongated curb extensions for some or most of a block (i.e., a widened sidewalk with lay-by areas) in areas where a full sidewalk widening would be desirable but some loading, drop-off, or parking access must be maintained
  • Cannot be used where curbside travel (including bus, bicycle, or general traffic) lane exists, such as those created through peak-period parking restrictions
  • Feasibility of curb extensions is evaluated based on engineer review of design vehicle turning movements and vehicle turning volumes

Design Guidelines

  • Curb extension width is typically two feet less than the width of the parking lane, but the curb extension can also extend to the bicycle lane when one is striped. Minimum curb extension length is typically equal to the full width of the crosswalk, however it can be longer when appropriate or necessary
  • A fire truck turning zone with a 50-foot outside radius should be maintained clear of physical obstructions (signs, planters, non-flexible bollards, trees)
  • When a curb extension conflicts with design vehicle turning movements, the curb extension should be reduced in size rather than eliminated wherever possible
  • At crossings that may have low pedestrian visibility, curb extension should be long enough to "daylight" the crossing, i.e., provide open sight-lines to the pedestrian crossing for approaching motorists. The additional curb extension space can be used to provide plantings or community facilities such as bicycle parking as long as visibility is not hindered
  • The design and placement of street furniture, trees, and plantings on a curb extension must not impede pedestrian flow, obstruct clear path, or interfere with "daylighting" the intersection, emergency operations, or sight lines
  • Curb extension must be designed so as to maintain drainage of stormwater from the gutter and not cause ponding; Depending on site-specific grading conditions this might include properly locating catch basins or utilizing design treatments that channel water through, around, or in between curb extension and the curbline
  • When space permits, more functional curb extension designs, such as those with green street/planted areas or community facilities such as seating or bicycle parking should be used whenever possible
  • Vertical elements should be used to alert drivers and snow plow operators to presence of the curb extension
  • To reduce the cost and implementation time of curb extension, trench drains can be considered instead of catch-basin relocation if a maintenance partner exists to clean the trench drain
  • When curb extension is used at a fire hydrant, the length of the curb extension should be equal to or greater than the no parking zone (typically 15 feet in either direction) and the hydrant should be moved onto the curb extension.
  • Paving on curb extension should match that of the surrounding sidewalks.

Traffic Diverters

Traffic diverters are a family of traffic calming treatments that can be used to slow, redirect or block motor vehicle traffic, primarily at intersections. This treatment is used on a limited basis.

In areas where a goal is to reduce motor vehicle through-traffic, it may be desirable to create physical barriers that make it impractical or impossible to use local streets for anything other than local access trips.

Benefits

  • Reduces or eliminates short-cut and cut-through traffic
  • When applied consistently to an area, reduces traffic speeds
  • Can green and beautify the streetscape with trees and/or vegetation, improving environmental quality and potentially incorporating stormwater source controls

Considerations

  • May require further changes to traffic network operation; consideration must be given to local traffic network connectivity, and a traffic diversion analysis should be performed
  • May impact street drainage or require catch basin relocation
  • May impact underground utilities
  • Emergency vehicle access needs must be accommodated
  • Landscaping or stormwater source controls require a partner for ongoing maintenance
  • If outfitted to capture stormwater, careful consideration must be given to design, overflow control, and plant species

Appropriate Conditions for Installation

  • Consider on local streets with speeding or cut-through/short-cutting issues

Design Guidelines

  • Design traffic diversion devices to impact motor vehicle movement but not bicycle movement; utilize bike channels or similar design strategies to allow passage by bicyclists
  • Include planted areas and stormwater source controls within traffic diverters wherever possible when a maintenance partner is identified
  • If work includes tree planting, consider the location of utility infrastructure, including NYC DEP sewers and water mains

Median Barriers

A median barrier is a type of traffic barrier, which is usually an elevated median or median safety island extended through an intersection to prevent left turns and through-movements to and from the intersecting street. This treatment is used on a limited basis.

Pedestrian access can be maintained with pedestrian refuges and bicycle access with gaps in the median. As with typical medians, trees or plantings can be included within the median barrier.

Benefits

  • See Benefits for traffic diverters
  • Enhances safety at intersection by reducing potential vehicle movements and conflicts, particularly left turns
  • Reduces risk of vehicle head-on collisions
  • Reduces risk of motorists running a red light or stop sign when approaching from side street
  • Calms traffic on side street by requiring turn and on major street by narrowing roadway
  • Enhances pedestrian safety and accessibility by reducing crossing distances and providing refuge for pedestrians to cross the road in stages

Appropriate Conditions for Installation

Design Guidelines

Raised Crossings

A raised crossing (e.g. raised walkway) is a marked pedestrian crosswalk at an intersection or a mid-block location constructed at a higher elevation than the adjacent roadway. This treatment is used on a limited basis.

A raised crossing is essentially a speed table, with the full width of the crosswalk contained within the flat portion of the table, usually 10- to 15-feet wide. It combines the benefits of a raised speed reducer with enhanced visibility for the pedestrian crossing.

Benefits

  • Compels drivers to travel at speeds no higher than the street's design speed
  • Improves drivers' awareness of presence of pedestrian crossing, particularly at mid-block crossing locations
  • Used at street gateways, can alert drivers that they are entering a slower-speed, pedestrian-oriented street environment
  • Allows convenient pedestrian circulation between high foot traffic destinations on opposite sides of a street

Considerations

  • May impact street drainage or require catch basin relocation

Appropriate Conditions for Installation

  • Existing stop-controlled crosswalks or other locations where demand exists for a stop-controlled pedestrian crossing that also meet the criteria for raised speed reducers
  • Consider at areas of particularly high pedestrian crossing demand on narrower streets (maximum of two moving lanes), such as locations with pedestrian generators (e.g., major commercial or cultural destinations, transit entrances, parks) on opposite sides of the street
  • Consider as a more robust option for mid-block crossings
  • Consider on the outer roadways of multi-lane boulevards at crossings
  • Avoid on arterial roadways

Design Guidelines

  • Appropriate warning signs and roadway markings should accompany raised crossing
  • Use signage or other methods to alert snow-clearing vehicle operators to the presence of raised crossing
  • Use enhanced, high-visibility street materials to further draw attention to raised crossing