A school bus approaches a railroad crossing with a traffic signal or a stop sign on the far side. How much room does school bus guidance say the bus needs beyond the tracks before it starts across?

Explanation

The bus needs enough containment or storage area on the far side to clear the tracks completely even if it has to stop there, and the manual's working estimate is the length of the bus plus 15 feet. The hazard at this kind of crossing is not the crossing itself but the stop on the other side, which can leave the rear of a long bus sitting on the rails with nowhere to go. That is why the driver is expected to know both the length of the bus and the size of the storage area at every crossing on the route and on any activity trip, and to simply not start across when the two do not fit. The wrong options fail in two ways. Clearing the front axle, or allowing one bus length measured from the near rail, both describe a distance that still leaves part of the bus over the rails, whether by counting only the front of the bus or by leaving out the margin for the rear overhang and the stopped vehicle ahead. Relying on the signal trusts a device that was never designed to protect a vehicle standing on a railroad track and that can turn red while the bus is mid-crossing. The 15 foot allowance is the manual's rule of thumb, not a federal figure: 49 CFR 383.123(a)(2)(iii) names State and Federal law on safely traversing railroad-highway grade crossings as a required knowledge area, and it sets no clearance distance.

Source: 49 CFR 383.123(a)(2)(iii)