Someone asked me for wheelchair ramp specifications -- so here are the ones from CMHC.
Specifications include: a ramp slopes no steeper than 1:12, max length of 9000mm between landings, an upstand curb 75 mm high (to stop from rolling off the side), guard rail mounted at a height of 200mm on each side of the ramp, have level landings at the bottom and top, and landings, landings should be at least 1500mm long by the full width of the ramp and should have a min. clear area of 600mmX1500mm free of door swings, slip resistant surfaces, junction between ramp and landing should provide a smooth transition, handrails should extend a min. of 300mm beyond the end of the ramp, tubular or oval handrails with a diameter of 30mm to 40mm are recommended to provide a comfortable grip. Handrails must extend beyond the top and bottom edge of the ramp.