You are approaching a railroad crossing and you do not see or hear a train. You must stop:

You must always stop before crossing railroad tracks if flashing red lights are activated, a crossing gate is lowered, a stop sign is posted, a flagger signals you to stop, or a train is visible or so close to the crossing that it would be hazardous to continue driving. If you are unsure if a train is too close for you to safely cross the tracks, stop. Never race a train.