To supersede the requirements of Sentence 3.4.1.6.(1) and permit an increase in the ratio of horizontal exits to all exits, on the basis that:
This is to limit the probability that persons will not have a choice of sufficient alternative exterior exit routes in the event that routes to horizontal exits are blocked or obstructed 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.