The crossing rules split drivers into two groups, and which group you are in depends on the vehicle and the load rather than on the crossing. § 392.10 lists the vehicles that must STOP at every grade crossing: every bus transporting passengers; every commercial motor vehicle carrying any quantity of Division 2.3 chlorine; every vehicle required to be marked or placarded with one of the classifications the section enumerates; every cargo tank motor vehicle used for hazardous materials, loaded or empty; every cargo tank carrying a commodity loaded above its flashpoint; and every cargo tank carrying a commodity under exemption. For those drivers the sequence is exact. Stop within 50 feet of the tracks and no closer than 15 feet. Then listen and look in each direction along the tracks for an approaching train, and ascertain that none is approaching. When it is safe, cross in a gear that will complete the crossing without a change of gears — and do not shift while on the tracks.

§ 392.10(b) then names five places where the stop is not required: a streetcar crossing or tracks used exclusively for industrial switching within a business district; a crossing where a police officer or crossing flagman directs traffic to proceed; a crossing controlled by a functioning highway traffic signal showing green, where local law permits crossing without slowing or stopping; an abandoned crossing marked with a sign saying the line is abandoned; and an industrial or spur line crossing marked “Exempt” — a sign that may only be erected by or with the consent of the appropriate State or local authority. Every other commercial motor vehicle falls under § 392.11 instead, which asks for something different rather than nothing: approach at a rate of speed that will permit stopping before the nearest rail, and do not drive onto the crossing until due caution has been taken to ascertain that the course is clear.

§ 392.12 then binds both groups equally, and it is the shortest rule in the chapter: no driver shall drive onto a highway-rail grade crossing without having sufficient space to drive COMPLETELY THROUGH it without stopping. Note what that rules out. Not just stopping on the tracks — entering a crossing when the traffic ahead might make you stop on them. The judgment has to be made before the front wheels move, from the space visible on the far side. § 392.14 asks for the same kind of anticipation in weather. Extreme caution shall be exercised when hazardous conditions — the section names snow, ice, sleet, fog, mist, rain, dust or smoke — adversely affect visibility or traction, and speed shall be reduced when they exist. If conditions become sufficiently dangerous, operation shall be DISCONTINUED and shall not be resumed until the vehicle can be safely operated. The one relief mirrors § 392.3’s: where compliance would increase the hazard to passengers, the vehicle may be operated to the nearest point at which their safety is assured.