To limit the probability that persons moving through a horizontal exit in an emergency situation will have difficulties in their movement, which could lead to delays in the evacuation or movement of persons to a safe place, which could lead to harm to persons.
To limit the probability that a person using a manual wheelchair or other manual mobility assistance device, or having other mobility limitations, will be unable to move through a horizontal exit in an emergency situation without assistance from another person, which could lead to delays in the evacuation or movement of persons to a safe place, which could lead to harm to persons.