When stopping at a railroad crossing, within what distance range from the nearest rail should a school bus driver stop?

49 CFR 392.10(a) (stop within 50 feet of, and not closer than 15 feet to, the track); AAMVA CDL Manual Section 10.4.3, p. 10-9

Stopping too close to the rail puts the front of the bus in a train's path if it overhangs the track; stopping too far back can block the driver's view of the crossing. The 15-to-50-foot range balances visibility against clearance, and it is an actual federal operating requirement, not just manual guidance.