54. Every bus or minibus, excluding those used as police wagons, shall comply with the following standards:(1) the passageway to the emergency exits shall be free of any encumbrance and, in the case of a vehicle equipped with wheelchair locking devices, allow wheelchairs to move about;
(2) the emergency window shall be securely mounted on its hinges;
(3) the emergency window exit release shall allow the window to be easily opened and closed from inside and, if so designed, from the outside, and the warning light or buzzer shall be adequate;
(4) the hatch of the roof emergency exit shall open outwards easily and adequately; and
(5) the signs provided by the manufacturer with respect to emergency exists shall be present and legible.