Types of Curb Ramps

Perpendicular Curb Ramps

• Perpendicular curb ramps are aligned with the curb at a 90-degree angle, so that users will be traveling perpendicular to traffic when they enter the street at the bottom of the ramp. It is best if the bottom of the ramp opens into the crosswalk. In addition, perpendicular curb ramps must include what is called a "top level landing," that is, a flat surface at the top of the ramp. This will ensure that wheelchair users will not have to change levels as they move along the path. Perpendicular curb ramps are expensive, and tend to create problems with a clear right-of-way.

Diagonal Curb Ramps

• Diagonal curb ramps run straight off the corner of the curb. They are cheaper to make because, unlike perpendicular curb ramps, only one ramp per corner is required. The main problem with this type of curb ramp is that it puts pedestrians potentially in harm's way, as they may be in the path of drivers who are traveling straight and turning. They also require a turn at the top and bottom of the ramp, and provide no alignment with the crosswalk, which can cause problems with turning.

Parallel Curb Ramps

• Parallel curb ramps run parallel to the direction of foot and vehicle traffic, creating a depression in the actual path of travel. They run down to a landing which leads into the crosswalk. These ramps allow for a minimal right-of-way, allow for smaller ramp grades, which makes them more wheelchair-friendly, makes the street access line up with the crosswalk, and allow for a level maneuvering area at the top of the ramp. Problems with parallel curb ramps include requiring pedestrians to navigate two ramp grades, and require careful construction at the bottom, as water and debris can easily accumulate.

Combined Perpendicular and Parallel Curb Ramps

• Combined perpendicular and parallel curb ramps combine some of the advantages of each type while minimizing the disadvantages. Like a parallel curb ramp, the level of the walk way gradually depresses around the curb, but a perpendicular lamp lies on each side of the corner. They are accessible, allow pedestrians to be aligned with the crosswalk, and limit to accumulation of debris, but also require a lot of space, and still requires passing pedestrians to negotiate a parallel ramp.