To limit the probability that the absence of a handrail extension at the top and bottom of a stairway or ramp will lead to persons not having positive feedback for determining the top and bottom of the stairway or ramp, which could lead to persons falling, which could lead to harm to persons.
To limit the probability that the absence of a handrail extension at the top and bottom of a stairway or ramp will lead to persons not having positive feedback for determining the top and bottom of the stairway or ramp, which could lead to inefficient movement in an emergency situation, which could lead to delays in the evacuation or movement of persons to a safe place, which could lead to harm to persons.