36 CFR Part 1192 Americans with Disabilities Act (ADA) Accessibility Guidelines for Transportation Vehicles (2016 Non-Rail Vehicle Guidelines)

T402.2 Design Load.

Ramps and bridgeplates 30 inches (760 mm) or more in length shall be designed to support a load of 600 pounds (273 kg) minimum, placed at the centroid of the ramp distributed over an area of 26 inches by 26 inches. The design load of ramps and bridgeplates less than 30 inches (760 mm) in length shall be 300 pounds (136 kg) minimum. The factor of safety for ramps and bridgeplates shall be 3 or more, based on the ultimate strength of the material.