Which signal indicates that you should stop at a railway crossing?

A flashing red light at a railway crossing is a clear and universally recognized signal that indicates you must stop. The purpose of this signal is to ensure the safety of both drivers and train passengers by providing a visual cue that a train is approaching. When you see a flashing red light, it is a warning that the tracks are active, and you should remain stopped until the lights stop flashing and it is safe to proceed.

In contrast, a yellow light typically indicates caution and may recommend a reduction of speed or a lookout for hazards, but it does not carry the same authority as a red light, especially in relation to railway crossings. Two white lights generally signify that a train is approaching from the opposite direction, indicating a need to be cautious but not specifically mandating a stop. A green light would not indicate any restriction on proceeding; in fact, it means go, which is not appropriate for a railway crossing situation where safety is of utmost importance.