Section 575IAC1-9-51. Lamps and signals; stop arm

   (a) Each bus must have a stop signal device to indicate that the bus is stopped. The device must meet the following specifications:

(1) The stop signal device must be a flat octagon-shaped device, approximately eighteen (18) inches wide and eighteen (18) inches long, exclusive of the mounting brackets, and meet Society of Automotive Engineers (SAE) specifications J-1133.

(2) Both sides of the device must be a bright red with a one-half (1/2) inch white border. The word "STOP" must be printed on both sides in white block-letters at least six (6) inches high. The sign, including the letters, must be reflective and must not lose more than twenty percent (20%) of its reflectivity when wet.

(3) The stop signal device must contain double-faced, alternately flashing four (4) inch-high red lamps, with one (1) lamp placed near the top and one (1) lamp placed near the bottom of the device.

(4) The device must be mounted outside and immediately below the driver's window.

(5) The stop signal device must have a driver-controlled mechanism, either mechanical, vacuum, electrical, or air, that will hold the device in an extended or retracted position to prevent whipping in the wind. The driver must be able to operate the mechanism while remaining in the normal driving position. Diesel engines without a chassis-installed vacuum or air source must use an electric stop signal device.

(6) A wind guard may be installed to prevent the stop signal device from whipping in the wind.

(7) An activated stop signal device must extend to ninety (90) degrees perpendicular to the bus, plus or minus five (5) degrees.

  (b) A red strobe light meeting SAE standards may be installed in the stop signal device.

  (c) School buses may be equipped with an additional rear stop signal device to indicate that the bus is stopped. The device must meet the following specifications:

(1) The rearmost stop signal device must not contain any lettering, symbols, or markings on the forward side.

(2) The rearmost stop signal device must be bright red in color and non-reflectorized on the forward side in accordance with FMVSS 131, S.5.2.3.

(3) The rearmost stop signal device must be mounted on the left side of the bus and not more than eight (8) feet from the rear of the bus.

(4) The rearmost stop signal device must be mounted at the same height as the stop signal device that is located immediately below the driver's window.

(5) An additional stop arm device may be installed on Type A school buses.

(State School Bus Committee; 575 IAC 1-9-51; filed Aug 15, 2014, 10:20 a.m.: 20140910-IR-575130244FRA; filed Oct 6, 2016, 2:09 p.m.: 20161102-IR-575150426FRA)