To limit the probability that a mismatch between winder configuration and the natural gait of most users will lead to:
This is to limit the probability of harm to persons.
To modify the application of Sentence 9.8.4.3.(2) for uniformity of treads in stairs within dwelling units where the occupant load is low and occupants are likely to be familiar with their surroundings, on the basis that a specific stair configuration has traditionally been used extensively within dwelling units without dramatic consequences for the safety of persons and that experience warrants its continued use.