Motor Vehicle Safety Regulations — 217
t is generated by the rotation about its minor axis of an ellipse having a major axis of 500 mm (20 inches) and a minor axis of 330 mm (13 inches); or (c) doors. (9) Every school bus shall be provided with, at the option of the manufacturer, (a) one rear emergency door that opens outward and is hinged on the right side for a bus with a GVWR of more than 4 536 kg (10,000 lb.); (b) at least one rear emergency door that opens outward and is hinged on either side for a bus with a GVWR of 4 536 kg (10,000 lb.) or less; or (c) the following emergency exits, namely, (i) one emergency door (A) hinged on its forward side, and (B) located on the left side of the bus in the rear half of the bus passenger compartment, and (ii) one push-out rear window that (A) provides a minimum opening clearance 400 mm (16 in.) high and 1 200 mm (48 in.) wide, (B) is capable of being released by the operation of not more than two mechanisms that are located in the high-force access region as shown in Figure 3C and that do not have to be operated simultaneously, and (C) for release and opening, requires a force of not more than 180 N (40 lb.) applied in the directions specified in subsections (13) and (14). (10) Every school bus shall be provided with a warning system that shall (a) be activated when the vehicle ignition is in the ON position and (i) any emergency exit of the bus is locked in such a manner that the release mechanism of the exit cannot be activated by a person at that exit without the use of a special device, such as a key, or special information, such as a lock combination, (ii) a release mechanism that opens an emergency exit is not in the fully latched position, or (iii) one or more emergency exits are not in the fully closed position; and (b) generate a continuous warning sound audible at the driver’s seating position and in the immediate vicinity of the emergency door or push-out window that caused the system to be activated. (11) Every push-out window or other emergency exit not required by subsection (9) shall have one or two release mechanisms located within the access regions shown in Figure 1, Figure 2 or Figure 3. (12) The lower edge of the low-force access region in Figure 1 and the lower edge of region B of the high-force access region in Figure 2 shall be located (a) 130 mm (five inches) above the adjacent seat, or (b) if an arm rest is fitted, 50 mm (two inches) above the arm rest, whichever is the higher. (13) When tested in accordance with the conditions set out in subsections (24) and (26) both before and after the window retention test described by subsection (2), every emergency exit of a bus, other than an emergency door required by subsection (9), shall allow manual release of the exit release mechanism by an occupant using, at the option of the manufacturer, (a) a low-force application of not more than 90 N (20 pounds) in a rotational or linear direction if the emergency exit release mechanism is located as shown in Figure 1 or Figure 3 of this section; or (b) a high-force application of not more than 270 N (60 pounds) in a linear direction perpendicular to the undisturbed emergency exit surface if the emergency exit release mechanism is located as shown in Figure 2 or Figure 3 of this section. (14) Every emergency exit release mechanism shall require for its operation not more than two applications of force, one of which must differ by 90 to 180 degrees from the direction of the initial push-out motion of the emergency exit. (15) Under the conditions set out in subsections (24) and (26), both before and after the window retention test described in subsection (2.1), every school bus emergency door shall be capable of being manually released by one person, from inside and outside the bus, using a force not exceeding 180 N (40 lb.) that is applied (a) within the access region for high forces shown in Figure 3B to this section for a side emergency exit door and in Figure 3D to this section for a rear emergency exit door