He did not stop his car at the red light.

The red traffic light indicates "stop".

The policeman told us not to cross the street against the red light.

It's dangerous for you to cross the street when the light is red.

Did you stop at the red light?

The light changed from red to green.

You ran a red light.

It raises a red flag for businessmen.

An impatient driver forced his way through the crossing against the red light.