To limit the probability that a person using a manual wheelchair or other manual mobility assistance device will not be able to rest and remain stationary while opening a door without the assistance of another person.
To limit the probability that the level area of a ramp will be of insufficient size to provide a clear width beyond the latch edge of the door, which could lead to a person using a manual wheelchair or other manual mobility assisting device being unable to negotiate the wheelchair past the door without assistance.