To minimize the risk of injury to persons as a
result of tripping, slipping, falling, contact, drowning or
To facilitate the timely movement of persons to a
safe place in an emergency.
Uniformity of rise along top or bottom risers in interior
and exterior stairs, for buildings to which Part 9 applies [see Sentence
188.8.131.52.(1) of Division A for application of
Part 9], where these risers adjoin a sloping finished walking surface.