A flashing red light means stop. Treat it exactly like a stop sign: come to a full stop at the line, yield to traffic and people who have the right-of-way, and go when it is safe.
You'll see flashing red lights at quiet intersections late at night, at intersections under construction, and sometimes during a partial power problem. They often pair with a flashing yellow light for the other road.
What to do
- Stop fully at the stop line (or before the crosswalk).
- Look left, right and left again.
- If the cross street has a flashing yellow, its traffic does not have to stop: wait until it is clear.
- If every approach has a flashing red, it works like an all-way stop: first to stop goes first.
- Go when it is your turn and the way is clear.
Flashing red vs flashing yellow vs dark
| Signal | Stop? | Then |
|---|---|---|
| Flashing red | Yes, full stop | Go when safe (stop-sign rules) |
| Flashing yellow | No | Slow down, watch for cross traffic |
| Dark (not working) | Yes | All-way stop rules |
| Solid red | Yes | Wait for green (right on red allowed after a stop unless posted) |
Where you'll see flashing red lights
Flashing red lights show up in a few predictable places. Many traffic signals switch to flashing mode late at night, with red for the side street and yellow for the main road. Some small towns use a single flashing red beacon hanging over an intersection instead of stop signs. Railroad crossings use pairs of flashing red lights that mean stop because a train is coming, which is a different rule: you stay stopped until the lights go off. And school buses flash red lights when they stop to load children.
The common thread: a flashing red always means come to a complete stop. What happens next depends on the situation, but the stop never changes.
On a permit test, flashing-light questions are usually quick points if you remember one pairing: red means stop, yellow means slow. The trick answers try to make a flashing red sound optional ("slow down and proceed") or a flashing yellow sound like a stop.
Practice it
See the lights and pick what you do in Signal LabStart ›Rule and sources: flashing red and flashing yellow. For what to do when the lights are completely dark, see traffic lights out.
