X02 New Construction: Minimum Requirements: X02.1 Public Sidewalks

X02.1 Public Sidewalks

X02.1.1 General.
Where provided, public sidewalks shall comply with this section.

X02.1.2 Pedestrian Access Route

X02.1.2.1 General. Where public sidewalks are provided, they shall contain a pedestrian access route. The pedestrian access route shall connect to elements required to be accessible in Section X02.3 and shall meet the requirements set forth in Section X02.1.1 through Section X02.1.7.

Discussion: The pedestrian access route must comply with the provisions of Section X02.1.1 through Section X02.1.7. However, if the public sidewalk is wider than the pedestrian access route, the portion of the public sidewalk outside the pedestrian access route is not required to comply with these sections. While the pedestrian access route is designed to be universally accessible, there are additional elements in the public sidewalk, such as stairs and handrails, that are used by some pedestrians with disabilities. These elements must also meet applicable standards in order to be accessible to those who choose to use them. The committee had a lengthy discussion of planning the public/private interface at the edge of the right-of-way to ensure access to new construction and to remove barriers to existing private sites and facilities that abut a new or altered public sidewalk. However, it was determined that conditions in the public right-of-way are so variable that it would be impossible to develop a provision covering such public/private coordination. The Access Board will use best practices case studies that illustrate a range of approaches as they develop technical assistance information during 2001.

X02.1.2.2 Reduced Vibration Zone. Within the pedestrian access route, there shall be an unobstructed reduced vibration zone meeting the requirements of this section. The reduced vibration zone shall be a contiguous part of the pedestrian access route that connects to elements required to be accessible in Section X02.3, and shall meet the requirements set forth in Section X02.1.1 through Section X02.1.7.

Advisory: : The reduced vibration zone is intended to result in an unobstructed, smooth, and navigable path that is aligned to be as direct and free of meanders as possible.

Discussion: The reduced vibration zone is a "path within a path;" that is, it may be wholly contained within the width of the pedestrian access route. Some pedestrians using wheelchairs or other mobility aids experience pain or difficulty when rolling over rough or jointed surfaces, which may preclude their ability to use the public sidewalk. The reduced vibration zone is intended to provide a place within the pedestrian access route where such impediments are minimized, while still allowing some design freedom within the remaining public sidewalk area.

Research need: The committee wished to adopt a standard for the smoothness of the pedestrian access route but was not able to identify suitable technical provisions, such as a measurement of the rolling vibration of pedestrian surfaces. Paved surfaces for vehicles are evaluated according to a roughness index (the IRI) for which there is an American Society for Testing and Materials (ASTM) measurement protocol that employs a profilometer. The committee encourages research to determine if the IRI could be adapted to the evaluation of pedestrian surfaces. The committee believes that research on the relationship of surface roughness, surface wavelength (amplitude and frequency), and caster and wheel diameter and materials may also be a fruitful area for research. In addition, ASTM standards are currently being developed for application in Hawaii. The committee recommends review of the Hawaii standard when available for possible incorporation into any new guidelines.

X02.1.3 Clear Width

X02.1.3.1 General. The minimum clear width of a pedestrian access route shall be 60 inches (1525mm), exclusive of the width of the curb. Within the pedestrian access route, the minimum clear width of the reduced vibration zone shall be 48 inches (1220mm), exclusive of the width of the curb.

Advisory: Designers are encouraged to provide additional width where possible, especially in high use areas such as in downtown urban environments, near shopping centers, schools, civic facilities. It is recommended that the pedestrian access route be no less than 72 inches wide in high use areas.

Discussion: It is the intent of this section to create a minimum safe navigation passage for people with disabilities. People with disabilities will be able to navigate the pedestrian access route more safely if the route is easily discernible and obstacles are eliminated. Public sidewalks that are at least 60 inches wide are the minimum width for turning a wheelchair and for allowing two wheelchair users to pass each other. The Access Board's Accessible Rights of Way: A Design Guide states that: 1) some pedestrians who use crutches need as much as 42 inches (1065mm) in width to achieve a comfortable gait; and 2) an individual traveling with a service animal or sighted guide will use a minimum of 48 inches (1220mm) of width for easy passage. Also, a 72-inch (1830mm) public sidewalk allows for two wheelchair users to travel side by side, provides a manageable area for a crutch user and a wheelchair user, and is the recommended minimum width for public sidewalks in high use areas. The curb width should not be used in calculating the width of the pedestrian access route since there is a possibility of a person with mobility impairment traveling at the outer edge and falling off the curb. It is helpful to think of a 48-inch-wide corridor of the pedestrian access route as "inviolate," the minimum to which the pedestrian access route can be reduced, corresponding with the continuous reduced vibration zone.

EXCEPTIONS:
1. Driveways and alleyways.
Where public sidewalks intersect driveways or alleyways, the width of the pedestrian access route may be reduced to 48 inches (1220mm) across the driveway.

Advisory: Excessive cross slope or change in cross slope on driveway aprons can be a significant barrier to public sidewalk use. Even with narrow public sidewalks along the curb, it is possible to design a public sidewalk to pass across the driveway apron without exceeding the 1:48 cross slope limitation. Existing non-complying aprons can be reconstructed to achieve a usable cross slope for a width of 48 inches. By breaking the driveway apron into three parts Ð the apron on the roadway side, the sidewalk, and the apron on the property side Ð vehicles must slow to negotiate the two steeper ramps on either side of the sidewalk crossing. When properly designed and constructed, these driveways will not cause vehicles to "bottom out."

Figure X02.1 A Sidewalk/Alley or Driveway Connections

Figure X02.1 A Sidewalk/Alley or Driveway Connections - Isometric views of five public sidewalk and driveway or alleyway connections.

Isometric views of five public sidewalk and driveway or alleyway connections. Illustrations show minimum PAR width of 48 inches (1220mm) at the driving area and indicate maximum allowable cross slopes.

Figure X02.1 B Reconstruction of Driveway Aprons

Isometric views of a public sidewalk and driveway showing before and after conditions. The before view shows a driveway crossing a public sidewalk and a typical steep cross slope condition. The after view shows transition ramps approaching a lowered driveway apron which allows a 48-inch wide PAR with 1:48 cross slope to complete the connection.

Isometric views of a public sidewalk and driveway showing before and after conditions. The before view shows a driveway crossing a public sidewalk and a typical steep cross slope condition. The after view shows transition ramps approaching a lowered driveway apron which allows a 48-inch wide PAR with 1:48 cross slope to complete the connection.

(EXCEPTIONS to X02.1.3.1, continued)
2. Parallel parking
. Where parallel parking spaces are provided adjacent to existing public sidewalks, and site constraints do not allow full compliance with the requirements of this section, the width of the pedestrian access route may be reduced to 48 inches (1220mm).

3. Accessible building entrances. Where construction is permitted in the sidewalk to provide an accessible entrance to an existing adjoining property, and site constraints do not allow full compliance with the requirements of this section, the width of the pedestrian access route may be reduced to 48 inches (1220 mm).

4. Street fixtures. Where insufficient public right-of-way is available to locate street fixtures outside the 60 inch (1525mm) minimum clear width, the pedestrian access route may be reduced to 48 inches (1220mm) for a length of 24 inches (610mm) maximum, provided that reduced width segments are separated by segments of the pedestrian access route that are 60 inches (1525mm) minimum in length and 60 inches (1525mm) minimum in width.

Advisory: Placement of street fixtures should be outside the usable area of the public sidewalk (the pedestrian access route plus any other area intended for pedestrian travel) to the maximum extent feasible.

Figure X02.1 C Placement of Street Fixtures

Plan view of a wall and street fixtures in relationship to the public sidewalk. Illustrates that the width of the pedestrian access route may be reduced to 48 inches and minimum spacing of 60 inches between objects intruding into the full 60-inch pedestrian access route.

Plan view of a wall and street fixtures in relationship to the public sidewalk. Illustrates that the width of the pedestrian access route may be reduced to 48 inches and minimum spacing of 60 inches between objects intruding into the full 60-inch pedestrian access route.

Discussion: The committee recognizes that public rights-of-way, unlike most corridors in buildings, are frequently the locations of numerous items of street furniture and fixtures that serve a wide variety of public and private purposes. In order to ensure that public sidewalks are accessible and usable by persons with disabilities, an unobstructed pedestrian access route must be provided. The committee also realizes that some flexibility is needed in placing utilities and other fixtures that share the public rights-of-way. Therefore, street fixtures, such as street light poles and bollards may be allowed to encroach slightly into the 60-inch pedestrian access route, though they should be located outside of the public sidewalk wherever possible. Street furniture, on the other hand, attracts stationary pedestrians, which can block the pedestrian access route further. Thus, fixed street furniture such as mailboxes, newspaper boxes, litter containers, benches, and bicycle racks should not be allowed within the pedestrian access route and should be located with their clear floor or ground space at the edge of public sidewalks wherever possible.

X02.1.4 Cross Slope.

X02.1.4.1 General. The cross slope of the pedestrian access route cross slope shall not exceed 1:48.

Discussion: This requirement is consistent with current and proposed ADAAG standards that set a maximum 1:48 cross slope on accessible routes.

X02.1.5 Grade.

X02.1.5.1 General. The minimum feasible running grade consistent with grades established for the adjacent roadway shall be provided in the pedestrian access route.

EXCEPTION: The running grade of a pedestrian access route may be steeper than the adjacent roadway, provided that the pedestrian access route grade is either:

  1. Less than 5%, or
  2. In compliance with Section X02.4, or
  3. In compliance with proposed ADAAG Section 405.

Advisory: : The grades of a pedestrian access route should be as flat and uniform as possible in order to maximize accessibility. When the grade of the adjacent roadway exceeds 5 percent, it may be possible to create an independent sidewalk and pedestrian access route that differs from the contiguous roadway. This may be accomplished by establishing a sidewalk profile that is higher or lower than the roadway profile or by using a switchback design of connected ramps and landings that allows for a lesser slope. Where sidewalk grades are contiguous with the adjacent roadway grades and are at a grade steeper than 5 percent, accessibility will be maximized if level landings and/or handrails can be provided.

Discussion: Where public sidewalks are located on independent vertical and/or horizontal alignments that are not related to roadways, they should comply with current and proposed ADAAG.

In some locations it is not feasible to construct a roadway at less than a 5 percent grade, and right-of-way constraints or lot configurations may preclude separating the pedestrian access route significantly from the roadway. In such cases the running grade of the pedestrian access route may be as steep as the running grade of the roadway.

X02.1.6 Surfaces.

X02.1.6.1 General. The surfaces of the pedestrian access route shall comply with proposed ADAAG Section 302 and shall be as free of jointed surfaces and as visually uniform as possible.

EXCEPTION: Surfaces may contain control joints and similar joints that are associated with established construction practices for those surfaces or structures that include pedestrian access routes.

Advisory: Individual paving units, bricks or other textured materials are examples of surfaces that are undesirable in the pedestrian access route because of the vibration they cause. They may, however, be used in the portions of the public sidewalk that do not contain the pedestrian access route. The purpose of the visually uniform surface is to provide uniformity in color along the pedestrian access route to avoid confusing persons with low vision.

Discussion: The requirement related to joints in the surface of the pedestrian access route is intended to eliminate, to the greatest extent possible, surfaces that tend to cause the front end of a wheelchair to vibrate or bounce as one travels across the surface. For many people, this vibration can cause pain or muscle spasms, possibly leading to a loss of control and maneuvering ability of the wheelchair. Allowances need to be made for expansion and contraction of the sidewalk material. This smooth surface would also serve as a reliable, uniform surface for the placement of crutches, free of unpredictable surface anomalies. The ADAAG Manual, developed by the Access Board in July 1998, states in Section 4.5.4, "Irregular paved surfaces, where jointed surfaces may be recessed below the level of the paving unit, can disrupt wheelchair maneuvering even if the differences in level are less than 1/4 inch." As stated on page 20 of FHWA's Designing Sidewalks and Trails for Access, "Surface quality significantly affects ease of travel for walking aid users. Grates and cracks wide enough to catch the tip of a cane can be potentially dangerous for walking-aid users. Icy or uneven surfaces can also be hazardous because they further reduce the already precarious stability of walking-aid users." The FHWA document further states, in section 6.3.3.1.4, "Although asphalt and concrete are the most common surfaces for sidewalks, many sidewalks are designed using decorative materials such as bricks or cobblestones. Although these materials improve the aesthetic quality of the sidewalk, they may increase the amount of work required for mobility. For example, tiles that are not spaced tightly together can cause grooves that catch wheelchair casters. These decorative surfaces may also create a bumpy ride that can be uncomfortable to those in wheelchairs. In addition, brick and cobblestone have a tendency to buckle creating changes in level and tripping hazards for people with visual impairments as well as ambulatory pedestrians with mobility impairments. For these reasons, brick and cobblestone sidewalks are not recommended." Creative alternatives to brick sidewalks include: colored concrete (stamped to look like brick); or concrete sidewalks with brick trim which preserves the decorative quality of brick but is an easier surface to negotiate.

Research need: The committee recognizes the advantages of requiring public sidewalks to have a visually uniform pavement surface that is monochromatic except for uniformly repeating patterns or markings, which are locational, directional, or cautionary, and encourages the development of more specific guidelines in this area.

The committee understands that the Access Board and the Construction Specifications Institute will pursue the issue of visual contrast in a joint technical assistance project in 2001 and recommends including guidelines developed from this or other research identified during this project.

X02.1.6.2 Utility covers, gratings and other covers. Utility covers, gratings, and other coverings over below-grade construction shall not be placed within the minimum clear width of the reduced vibration zone.

Advisory:Placement of utility covers, gratings and other covers should be outside the entire public sidewalk to the maximum extent feasible.

X02.1.6.3 Surface gaps at rail crossings.

(A) General. Where the pedestrian access route crosses rail systems at grade, the horizontal gap at the inner edge of each rail shall be constructed to the minimum dimension necessary to allow passage of railroad car wheel flanges and shall not exceed 2 1/2 inches maximum. This allowance for a gap of 2-1/2-inches shall expire four years after the Access Board publishes the final rule on public rights-of-way, after which time the maximum gap shall be in accordance with proposed ADAAG Section 302.3 without the exception allowed in proposed ADAAG Section 1003.

EXCEPTION: On tracks that carry freight rail, the maximum horizontal gap is permitted to be 3 inches. This allowance for a gap of 3 inches shall expire four years after the Access Board publishes the final rule on public rights-of-way, after which time the maximum gap shall be in accordance with proposed ADAAG Section 302.3 without the exception allowed in proposed ADAAG Section 1003.

Advisory:Horizontal gap width shall be measured from the gauge face of the rail to the edge of the pavement. Where track junctions occur at street intersections, the pedestrian access route should avoid being routed over the switch points or frogs, which of physical necessity involve greater gaps than flangeways, or over raised guard surfaces of girder rails at curves. Where practicable, newly constructed pedestrian paths should intersect rail crossings at right angles.

Discussion: Current technology does not provide a practicable solution for eliminating large gaps in the surface around rails. However, any horizontal gap in the surface paving greater than 1/2 inch can trap a wheelchair wheel, which makes development of a filler or other solution an urgent need. The committee recognized that the technical requirements for such a filler are formidable, since a filler that did not work perfectly could result in derailment, but there was strong support on the committee for a recommendation that would provide some incentive to the railroad industry to undertake and complete research and development to remedy this dangerous condition.

Research need: The committee is concerned that no technology currently exists to ameliorate the hazardous flangeway gap where light and heavy rail lines cross pedestrian ways and recommends research on a practicable solution. The Association of American Railroads has proposed a Transportation Research Board (TRB) project for 2001-2004 to involve the user community of the Access Board, FHWA, State departments of transportation, local road and street agencies, transit agencies, the Federal Transit Administration and the Federal Railroad Administration.

(B) Detectable warnings. Where rail systems cross pedestrian facilities that are not shared with vehicular ways, such as public sidewalks and pedestrian plazas, a detectable warning shall be provided in compliance with Section X02.5.7.

Advisory: Detectable warnings are not recommended at the trackway when the rail crossing is within the vehicular way, such as a trackway crossing a crosswalk within a roadway.

Discussion: When a pedestrian who is blind or visually impaired is in the crosswalk, a detectable warning installed for a rail crossing could be confusing and be mistaken as an indication of the other side of the street or as a median refuge. The detectable warning at each sidewalk/street transition will provide an indication of the presence of vehicular traffic of any type within the vehicular way.

X02.1.7 Changes in Level.

X02.1.7.1 General. Where changes in level are permitted in the pedestrian access route they shall comply with proposed ADAAG Section 303.

Advisory: Changes in level between 1/4 inch and 1/2 inch are highly discouraged, even if permitted when beveled, in the public right-of-way. Changes in level exceeding 1/4 inch should be spaced at least 24 inches apart in the predominant direction of pedestrian travel to accommodate the average wheelbase of a wheelchair. 

Discussion: Abrupt changes in level can create surface bumps that jar the front wheels of a wheel chair and make passage difficult for people with mobility impairments. Decorative deeply stamped or heavily jointed surface treatments also provide for irregular, rough surfaces that preclude, make difficult, or make painful passage by persons who use wheelchairs and other mobility aids. An abrupt vertical change in level greater than 1/4 inch can impede forward travel with a wheelchair.

The committee considered limiting the number of abrupt vertical surface changes that exceed 1/4 inch that could be introduced along a length of the pedestrian access route. It was agreed that the standard 24-inch length of a wheelchair wheelbase could serve as a minimum distance between changes.

X02.1.7.2 Changes in level at rail crossings. Where the pedestrian access route crosses rail systems at grade, the surface of the pedestrian access route shall be level and flush with the top of the rail at the outer edge and between the rails.

X02.1.8 Stairs

X02.1.8.1 General. Where provided in public right-of-way, stairs shall comply with proposed ADAAG Section 504. Stairs shall not be part of the pedestrian access route.

X02.1.8.2 Visual contrast at the leading edges of steps. Each tread of stairs in the public right-of-way shall have a high visual contrast strip marking the full width of the tread for a depth of 2 inches minimum from the leading edge of the tread.

Figure X02.1 D Visual Contrast at Steps

Isometric views of treads and risers indicating contrast strip at leading edge. One shows the strip limited to the flat surface of the tread, one shows the strip wrapping over the nose of the tread.

Isometric views of treads and risers indicating contrast strip at leading edge. One shows the strip limited to the flat surface of the tread, one shows the strip wrapping over the nose of the tread.

Discussion: While stairways are not considered part of a pedestrian access route, they are often constructed at pedestrian grade separations that are also served by elevators or a ramping system that does provide accessibility. Often persons with low vision are also elderly and prefer to use stairs rather than ramps because of joint deterioration, which causes difficulty in negotiating ramps. Providing higher contrast and improved visibility of stairways significantly improves these users' ability to negotiate stairways. Marking the lead 2 inches of tread the full width of the step with a strip of high visual contrast or safety yellow material will improve visibility.

X02.1.9 Elevators and Lifts.

X02.1.9.1 General. Where provided in public rights-of-way, elevators shall comply with proposed ADAAG Section 407 and lifts shall comply with proposed ADAAG Section 408 and shall remain unlocked during the operating hours of the facility served by the elevator.

Discussion: The requirement that elevators and lifts remain unlocked is necessary to ensure that they are independently operable and available when the facility they serve is open for use by the public.

Frontier issue: The committee discussed the fact that larger wheelchairs and electric scooters are used more frequently in the outdoor environment and that the clear ground space of 32 inches by 48 inches provided in proposed ADAAG Section 408 may not accommodate these larger mobility aids. In some sections, such as for the approach to push buttons, the committee recommended a larger clear ground space. The committee suggests future work to establish a uniform recommendation on these dimensions for outdoor environments.

X02.1.10 Separation.

X02.1.10.1 General. Reserved

Advisory: Designers should consider providing sidewalks with both a vertical and horizontal separation from the adjacent roadway. Vertical separation can be created through the installation of curbs. Horizontal separation should be at least 24 inches (610mm) wide, and can be created through the installation of landscaping or furniture zones for benches, planters, literature display boxes, or similar clearly defined features or surfaces that will help guide persons who may otherwise unintentionally enter the vehicular way.

Discussion: The committee encourages the use of planting strips or similar distinct features or surfaces to separate the sidewalk from the roadway and curb, to provide an edge for visual and cane travel, to accommodate public sidewalk elements and furniture, and to help ensure the border width necessary to accommodate curb ramps.

The committee considered requiring the acquisition of sufficient ROW width to ensure public sidewalk accessibility. However, it was recognized that ROW conditions are so variable that it would not be possible to develop provisions applicable to a wide range of locations and circumstances.

X02.1.11 Edge Conditions.

1

X02.1.11.1 General. Reserved.

Advisories:
(A) Tactile and visual cues.
Pedestrians with visual impairments use visual and tactile boundaries (shorelines) for directional orientation. Public sidewalks with clearly defined edges will be more accessible for these pedestrians. Where public sidewalks abut other paved areas such as parking lots and pedestrian plazas, the use of a visually contrasting and tactile material at the edge of the pedestrian route is desirable.

Discussion: Blind and low vision pedestrians use visual and tactile boundaries (shorelines) for directional orientation in the public right-of-way.

(B) Edge Protection. Edge protection adjacent to public sidewalks containing pedestrian access routes is desirable in many instances because persons with disabilities often have limited agility and therefore have difficulty recovering if they encounter an uneven or potentially hazardous edge condition. Where provided, edge protection should be a minimum of 18 inches (450 mm) wide and consisting of a physical barrier such as a beam, curb, wall, shrubbery, railing or fence is preferred.

Discussion: The committee discussed the need for a safe edge condition along the public sidewalk. People with disabilities often have limited agility and need additional protection if there is a drop off or other potential hazard next to the public right-of-way. Where buildings abut the public sidewalk, they provide a clearly defined edge to the pedestrian circulation area. Where no building is present, a landscaped or other clearly defined space, level with the public sidewalk, provides a discernible edge for the pedestrian. Where the landscaped or other clearly defined space is not generally level or cannot be provided, or where slopes steeper than 1:3 abut the sidewalk, other edge protection should be considered.

X02.1.12 Handrails.

X02.1.12.1 General. Where provided in the public right-of-way, handrails shall comply with proposed ADAAG Section 505.

Advisory: Placement of the handrail extension return at a height lower than 27 inches will improve detectability for blind pedestrians.

X02.1.13 Parking structure exit warnings.

X02.1.13.1 General. Reserved.

Advisory:Where the public sidewalk crosses a vehicular exit for a parking structure, a vehicle-triggered audible and visual warning may be useful for all pedestrians, especially those with visual and hearing impairments. Research is needed to determine the specifications for such a warning system. Developers of parking structures are encouraged to provide drivers exiting the structure with an alert when a pedestrian is present.

Research need: The committee recommends that the Board undertake research to determine the specifications for a warning system to alert pedestrians of the approach of a vehicle exiting a parking structure. The system should ensure consistency of interpretation. The committee recommends that the system:

  1. Have an alarm that will not be confused with an Accessible Pedestrian Signal;
  2. Have an alarm that will not be confused with a heavy vehicle back-up sound;
  3. Have an alarm that is volume responsive to ambient sound; 5 dB above ambient noise level, and a maximum of 89dB is suggested as a starting point.

The committee also recommends research on pedestrian sensor systems that can advise the exiting motorist of the presence of approaching pedestrian traffic.