At least one elevator car serving all building levels shall be made available for emergency use and shall contain the following:
1. A minimum inside car platform of 4 feet 3 inches deep by 6 feet 8 inches wide with a minimum clear opening width of 42 inches, unless otherwise designed and approved to provide equivalent utility to accommodate an ambulance stretcher having a minimum size of 24 inches by 84 inches in its horizontal position.
2. The elevator shall be subject to control from the building control station.
3. The elevator shall be interconnected with the standby power system.
4. The elevator shall be identified with a permanent sign installed adjacent to the elevator control panel in the building control station.