2010 ADAS 406.4 Curb Ramp Landings
Landings shall be provided at the tops of curb ramps. The landing clear length shall be 36 inches minimum. The landing clear width shall be at least as wide as the curb ramp, excluding flared sides, leading to the landing.
EXCEPTION: In alterations, where there is no landing at the top of curb ramps, curb ramp flares shall be provided and shall not be steeper than 1:12.
Code according to 2010 ADAS. Check your state’s accessibility laws. Some states such as California, Georgia and Florida have additional requirements and standards.