Curb Ramps, Walks, and Sidewalks Must Meet ADA Accessibility Requirements
Nearly every landscape architecture project includes curb ramps, walks, or sidewalks. Do you know all of the extensive regulations that dictate how these pedestrian circulation features are designed? By the end of this article, you will understand the basic requirements for curb ramps, walks, and sidewalks you need to pass the California Supplemental Exam (CSE) for landscape architects.
Perpendicular Curb Ramps
Curb ramps must be identified on the site plan and must match the details included in the document package. Include a detail of the curb ramp drafted at 1/4″ = 1′-0″.
Ramps cannot project into vehicle traffic lanes or accessible parking spaces. The minimum width of the ramp (not including side glares) is 48″. Include spot elevations on the top and bottom of the ramp. The ramp slope may not exceed 8.3%. Also indicate the flair slope. If the top landing of the curb ramp is less than 48″, the maximum grade for flair the is 8.3%. However, if there is at least 48″ at the top landing of a curb ramp, the maximum flair slope can be up to 10%.
Curb ramps adjacent to vehicular traffic need to have a detectable warning surface (i.e. truncated domes) where the ramp joins traffic.
If the ramp is perpendicular to traffic, the entire ramp surface shall be covered with a detectable warning surface.
For ramps that are parallel to vehicular traffic, a three foot wide band needs to parallel the ramp where it meets traffic.
Side Ramps and Combination Ramps
Unlike perpendicular ramps that lead directly into traffic, side ramps parallel the flow of traffic.
Combination ramps blend the best of both worlds by having a ramp parallel to traffic which turns 90 degrees to cross traffic perpendicularly. Ramp slopes cannot exceed 8.3%. Unlike the perpendicular ramp, the width of the side ramp base must be 60″ wide. Ramps leading to the landing may still be 48″ wide. A 36″ wide detectable warning surface must be placed where the ramp enters traffic.
Pedestrian Crossings At Medians
There must be an accessible pedestrian route across medians if the accessible path of travel crosses a street with a median.
A series of ramps can be used to raise the user from street level to the median grade and then return them to the street grade on the other side. As with other ramps, median crossing ramps cannot exceed 8.3%.
Detectable Warning Surface Options
Designers have a couple of options for detectable warning surfaces. First, you can use raised truncated domes in a grid pattern. Second, you can use highly contrasting dark on light colors. The detectable warning shall be slip-resistant.
Provide a 12″ wide grooved band around the upper part of the curb ramp and flares.
Walks and Sidewalks
On new construction and renovation, all walks and sidewalks must be accessible. Changes in material and connection to existing walks are of particular concern and require a particular detail to demonstrate to the plan checker that these transition areas meet accessibility standards. Vertical changes in level along the accessible route of travel cannot exceed 1/4”. Level changes in the accessible route between 1/4” and 1/2″ must be beveled at 1:2 max slope. Walks need to be slip resistant, firm, and have a continuous common surface.
Sidewalks must be at least 48” wide. If a wheelchair needs to make a 180 degree turn, the minimum width is 60”. Required sidewalk width must be measured from the back of the curb.
Provide spot elevation and gradients to show how slope requirements are met. Slope perpendicular to the direction of travel (cross slope) shall not exceed 2%. At driveway, show how the 2% cross slope requirement is met. At a minimum, provide and indicate a 48” wide portion of the sidewalk to comply. Provide a section through driveway. Provide a level resting area 5’ in length at intervals of 400’ maximum, or indicate that slope in the direction of travel is 2% or less by providing spot elevations. Provide a passing space, measuring 60” x 60” every 200’ min, or indicate width of walk to be 60” or more.
At doors and gates, provide level areas with a maximum slope of 2%.
Walks, sidewalks, and pedestrian ways shall be free of gratings whenever possible. Identify location of all gratings within the path of travel and provide cut sheet of gratings for back check review. If gratings are located in walking surfaces, then grate openings cannot exceed 1/2″ in the direction of travel flow. Elongated openings should be placed perpendicular to the dominant direction of travel.
If the level change between walk/sidewalk and adjacent surface exceeds 4” in height, provide detail and indicate a 6” warning curb or appropriate guide rails. If the level change between walk/sidewalk and adjacent surface exceeds 30 inches in height, provide a detail and indicate guard rails will be 42” above finish grade for safety.
Summary of ADA Walks, Sidewalks, and Curb Ramps
As you can see, there are a few different ways you can meet ADA and California state accessibility requirements with curb ramps, walks, and sidewalks. The most important things to remember are:
- Keep grades less than 8.33 percent on the accessible path of travel
- Include a detectable warning surface where traffic meets the ramp
- Include handrails if there is a height difference greater than 30 inches between the walk and surrounding areas.
Just remember these basic facts about accessible walks and pedestrian curb ramps and you should be able to demonstrate compentency on the California Supplemental Exam for landscape architects.
If you would like more information about tips and tricks to prepare for the CSE, please consider signing up for the CSE mailing list and news letter. Thanks and good luck preparing for the CSE for landscape architects.