From the NARCOA rulebook:
"5. GRADE CROSSINGS. Motorcars do not have the right-of-way at grade crossings. Motorcars must be prepared to stop short of all grade crossings and proceed only when safe to do so. Be prepared to stop for vehicles and pedestrians that may run around crossing gates or flaggers. Check flangeways for obstructions and make sure that you have room on the other side of the crossing before proceeding.
Automatic grade crossing signals will not ordinarily be activated. When they are activated, however, the protection may be limited because waiting traffic expecting trains may not see motorcars and may ignore warning signals. No motorcar may enter a grade crossing until it is safe to do so. Horns shall not be used as a substitute for the crossing rules above"
Note that this was not a NARCOA excursion so the rulebook could be considered meaningless. Fairmont must have thought similarly or they wouldn't have put insulating cones behind the wheels.
Some automobile drivers assume they have the right of way, and others assume anything on the tracks has right of way so this is a constant source of concern as an operator.
Interestingly, we (the Boulder County group) have a U.P. Fairmont speeder. Noticed yesterday that the railroad specifically welded a piece of metal between each of the front wheels and the axle such that their car WOULD set off crossing signals/lights/etc. Guess they didn't like to yield.
Chris Weaver