§571.131. Standard No. 131; School bus pedestrian safety devices. — Inbound Citations

For the purposes of this subchapter, the following definitions apply:

(c) The inner surface of the glazing at the center of force application has moved relative to the window frame, along a line perpendicular to the undisturbed inner surface, a distance equal to one-half of the square root of the minimum surface dimension measured through the center of the area of the entire sheet of window glazing.

S5.1.1 An increasing force shall be applied to the window glazing through the head form specified in Figure 4, outward and perpendicular to the undisturbed inside surface at the center of the area of each sheet of window glazing, with a head form travel of 2 inches per minute.

S5.1.2 The requirements of this standard do not apply to a window whose minimum surface dimension measured through the center of its area is less than 8 inches.

S5.2 Provision of emergency exits.

S5.2.1 Buses other than school buses shall meet the requirements of either S5.2.2 or S5.2.3. School buses shall meet the requirements of S5.2.3.

S5.2.1.1 A bus with GVWR of more than 10,000 pounds may satisfy the unobstructed openings requirement by providing at least one side door for each three passenger seating positions in the vehicle.

S5.2.2 Buses other than school buses.

S5.2.2.1 Buses other than school buses shall provide unobstructed openings for emergency exit which collectively amount, in total square centimeters, to at least 432 times the number of designated seating positions on the bus. At least 40 percent of the total required area of unobstructed openings, computed in the above manner, shall be provided on each side of a bus. However, in determining the total unobstructed openings provided by a bus, no emergency exit, regardless of its area, shall be credited with more than 3,458 square centimeters of the total area requirement.

S5.2.2.2 Buses with GVWR of more than 10,000 pounds. Buses with a GVWR of more than 10,000 pounds shall meet the unobstructed openings requirements in S5.2.2.1 by providing side exits and at least one rear exit that conforms to S5.3 through S5.5. The rear exit shall meet the requirements of S5.3 through S5.5 when the bus is upright and when the bus is overturned on either side, with the occupant standing facing the exit. When the bus configuration precludes installation of an accessible rear exit, a roof exit that meets the requirements of S5.3 through S5.5 when the bus is overturned on either side, with the occupant standing facing the exit, shall be provided in the rear half of the bus.

S5.2.2.3 Buses with GVWR of 10,000 pounds or less. Buses other than school buses with GVWR of 10,000 pounds or less may meet the unobstructed openings requirement in S5.2.2.1 by providing:

(10) SAE Recommended Practice J575-1983, “Tests for Motor Vehicle Lighting Devices and Components,” revised July 1983, into § 571.131.