To limit the probability that handrails or constructions
below handrails will project an excessive distance into the required
width of stairways or ramps, which could lead to:
compromised use of the stairway or ramp, or
compromised use of the stairway or ramp in an emergency,
which could lead to delays in the evacuation or movement of persons
to a safe place.
This is to limit the probability of
harm to persons.