What does a red flashing light at a railway crossing indicate?

A red flashing light at a railway crossing serves as a clear warning that a train is approaching, and it is imperative for vehicles to stop. This signal is designed to enhance safety, alerting drivers to the immediate danger posed by an oncoming train, which can travel at high speeds and requires significant distance to stop. The red flashing light is a universal symbol that indicates that the crossing is not safe for passage; therefore, stopping is the only safe action to take.

The other options suggest levels of caution or clearance to proceed, which would not only misinterpret the meaning of the warning signal but could also lead to dangerous situations. Understanding that the red flashing light indicates an oncoming train prepares drivers to act appropriately and prioritize safety when approaching railway crossings.