Passed in 1990, the ADA (Americans with Disabilities Act) is a federal civil rights law that prohibits discrimination against people with disabilities in everyday activities. The following specs for mobility ramps are published ADA Accessibility Guidelines as amended through September 2002. To see the entire document click here.
General. Any part of an accessible route with a slope greater than 1:20 shall be considered a ramp. Ramps are essential for wheelchair users if elevators or lifts are not available to connect different levels. However, some people who use walking aids have difficulty with ramps and prefer stairs.
Slope and Rise. The least possible slope shall be used for any ramp. The maximum slope of a ramp in new construction shall be 1:12. The maximum rise for any run shall be 30 in (760 mm). Curb ramps and ramps to be constructed on existing sites or in existing buildings or facilities may have different slopes and rises if space limitations prohibit the use of a 1:12 slope or less. These allowable differences are as follows:
(1) A slope between 1:10 and 1:12 is allowed for a maximum rise of 6 inches (150 mm).
(2) A slope between 1:8 and 1:10 is allowed for a maximum rise of 3 inches (75 mm). A slope steeper than 1:8 is not allowed. Ramp slopes between 1:16 and 1:20 are preferred. The ability to manage an incline is related to both its slope and its length. Wheelchair users with disabilities affecting their arms or with low stamina have serious difficulty using inclines. Most ambulatory people and most people who use wheelchairs can manage a slope of 1:16. Many people cannot manage a slope of 1:12 for 30 ft (9 m). Try our new mobility ramp calculator!
Clear Width. The minimum clear width of a ramp shall be 36 in (915 mm).
Landings. Ramps shall have level landings at bottom and top of each ramp and each ramp run. Landings shall have the following features:
(1) The landing shall be at least as wide as the ramp run leading to it.
(2) The landing length shall be a minimum of 60 in (1525 mm) clear.
(3) If ramps change direction at landings, the minimum landing size shall be 60 in by 60 in. (1525 mm by 1525 mm).
Level landings are essential toward maintaining an aggregate slope that complies with these guidelines. A ramp landing that is not level causes individuals using wheelchairs to tip backward or bottom out when the ramp is approached.
Handrails. If a ramp run has a rise greater than 6 in (150 mm) or a horizontal projection greater than 72 in (1830 mm), then it shall have handrails on both sides. Handrails are not required on curb ramps or adjacent to seating in assembly areas. Handrails shall have the following features:
(1) Handrails shall be provided along both sides of ramp segments. The inside handrail on switchback or dogleg ramps shall always be continuous.
(2) If handrails are not continuous, they shall extend at least 12 in (305 mm) beyond the top and bottom of the ramp segment and shall be parallel with the floor or ground surface.
(3) The clear space between the handrail and the wall shall be 1 – 1/2 in (38 mm).
(4) Gripping surfaces shall be continuous.
(5) Top of handrail gripping surfaces shall be mounted between 34 in and 38 in (865 mm and 965 mm) above ramp surfaces.
(6) Ends of handrails shall be either rounded or returned smoothly to floor, wall, or post.
(7) Handrails shall not rotate within their fittings.
The requirements for stair and ramp handrails in this guideline are for adults. When children are principal users in a building or facility (e.g. elementary schools), a second set of handrails at an appropriate height can assist them and aid in preventing accidents. A maximum height of 28 inches measured to the top of the gripping surface from the ramp surface or stair nosing is recommended for handrails designed for children. Sufficient vertical clearance between upper and lower handrails (9 inches minimum) should be provided to help prevent entrapment.
Cross Slope and Surfaces. The cross slope of ramp surfaces shall be no greater than 1:50.
Edge Protection. Ramps and landings with drop-offs shall have curbs, walls, railings, or projecting surfaces that prevent people from slipping off the ramp. Curbs shall be a minimum of 2 in (50 mm) high.
Outdoor Conditions. Outdoor ramps and their approaches shall be designed so that water will not accumulate on walking surfaces.
