The Americans with Disabilities Act (ADA) has created design guidelines to ensure that transportation facilities are constructed to a set of standards that ensures accessibility for the disabled. Sidewalks are one of the most common pieces of transportation infrastructure, yet if not accessible, they can pose great challenges and danger to anyone in a wheelchair or with crutches. The ADA provides standards to help anyone constructing sidewalks do so in a safe, accessible manner.
TL;DR (Too Long; Didn't Read)
The ADA specifies the width, slope, texture required for public sidewalks, as well as how curbs are designed and the proximity to obstructions.
Sidewalk Legal Requirements
Public entities such as city governments and transit agencies are required to construct facilities in accordance with ADA standards. These standards apply to all new construction; however, the ADA also requires that public entities retrofit any public facilities to these standards to ensure equal access. These requirements include sidewalks and curb ramps, which must be retrofitted to meet all current standards. Any non-compliant sidewalks or curb ramps must be upgraded to meet current standards whenever any alterations, such as road surfacing, are carried out.
Sidewalk width requirements exist to make sure sidewalks are accessible for use by wheelchair-bound individuals. The minimum width for an ADA-compliant sidewalk is 36 inches (3 feet), though sidewalks can be constructed wider than this. If sidewalks are less than 60 inches (5 feet) across, passing spaces must be constructed at set intervals. These passing spaces must measure at least 60 inches on all sides, and must be located at least every 200 feet.
Sidewalk Surface Texture
Surface textures are important to ensure disabled individuals with mobility devices can safety traverse the sidewalk. The texture of a sidewalk must be firm, stable and slip-resistant. Care should be taken to ensure any concrete finishing meets these requirements. Additionally, any grates inset into the sidewalk must comply; to ensure that mobility devices do not get stuck, any openings in the grate can be no larger than ½ inch across.
Sidewalks also must meet slope requirements. A sidewalk must have a slope of less than 1:20; otherwise it will be considered a ramp, and will be subject to a different set of ADA standards. Further, any changes to elevation in the sidewalk must be considered. A increase in elevation of more than ½ inch exceeding the allowable slope will require the construction of a ramp, elevator or other compliant facility. ADA-compliant sidewalks must provide an alternative to stairs and escalators.
Curb ramps are required wherever a sidewalk crosses a curb. This is particularly important at street intersections, where individuals will interact with traffic. These ramps must have a slope of less than 1:12, must be at least 36 inches wide and must contain a detectable warning device with a raised dome surface and contrasting color. Ramps must not project into the street, and where there is a marked crosswalk, the ramp must be contained entirely in the width of the crosswalk.
Sidewalks may be located near obstructions, such as telephone poles, traffic signal cabinets or other utilities and infrastructure. Where such obstructions exist, the sidewalk must be constructed to allow the minimum width requirement of 36 inches between the edge of an obstruction and the edge of the sidewalk. In some cases, if a sidewalk cannot be constructed to comply with this guideline, the obstruction may need to be removed or relocated.