76. Where a school bus is equipped in front with a safety device that may be activated by the driver to keep schoolchildren at a distance from the road vehicle, the crossing control arm shall(1) be designed in such a manner that a force of 50 newtons applied to its centre is sufficient to push or pull the arm;
(2) be fully extended and at right angles to the bus within no less than 2 seconds and no more than 4 seconds after being activated; and
(3) not have any pointed or sharp edges.