¼ inch is the maximum. 

34 inches is the maximum height.

36 inches is the maximum height.

8.33% is the maximum for a ramp slope. 

The slope requirements for different parts of an accessible route vary.

Walkways 5%
Ramps 8.33%
Landings 2%
Elevator car 2%
Accessible parking 2%

30” x 48” is the minimum width. 

The clear width of walking surfaces must be 36 inches minimum

15” minimum
48” maximum

36” minimum, if serving elements are on only one side; otherwise 44” minimum.

Van stall must be 9’ wide (with 8’ wide loading area) by 18’ long, or 12’ wide (with 5’ wide loading area) by 18’ long.