What does a flashing red traffic light mean?

A flashing red traffic light means the same thing as a stop sign: come to a complete stop, yield to other traffic and pedestrians as required, and proceed only when it is safe. A flashing yellow light, by contrast, means proceed with caution — slow down and be alert, but you do not have to stop. Flashing signals are often used at night or at intersections where full signal operation is not needed. Treating a flashing red exactly like a stop sign — full stop, then go when clear — is standard intersection knowledge tested on the permit exam.