You are at the crossing. The white X works like a yield sign to the train: rail traffic always has the right of way.
Yield to any train. If lights flash or gates lower, stop behind the line and stay until gates rise fully. Never stop on the tracks, even in slow traffic.
The circle warns ahead; the X marks the spot. Treat the X as a yield sign whose other vehicle weighs 10,000 tons.
Entering the crossing before the far side is clear. If traffic could trap you on the rails, wait behind the line until there is room to cross completely.
Signs that live in the same family, or get confused with this one.
Prefer to study on your phone, in your own language? The same questions live in the app — 19 languages, all 50 states, every answer explained.