Traffic lights: what they mean
Red and red with amber mean stop. Green means go if the way is clear. Amber means stop, unless stopping might cause a collision.
What do traffic lights mean?
Red means stop behind the stop line. Red and amber together also mean stop. Green means you may go if the way is clear. Take extra care when turning and give way to pedestrians who are crossing, says Know your traffic signs.
Amber means stop. Under rule 175, you may continue only if you have already crossed the line or are so close that stopping might cause a collision.
Quick quiz
What does the picture at the top of this page show?
- This lane is closed to you.
- Red, red and amber, green, amber: what each means.
- The temporary restrictions end here.
Show answer
B. Red, red and amber, green, amber: what each means. The colours tell you when to stop and when you may go if the way is clear (Know your traffic signs). Source: Know your traffic signs: traffic signals, GOV.UK; The Highway Code, rule 175, GOV.UK
Where will you see it?
At junctions controlled by traffic lights, with primary signals at the stop line and usually another set across the junction.
What should you do?
Wait behind the stop line when red or red and amber show. On green, check that the way is clear and give way to pedestrians who are crossing.
What do people get wrong?
Red and amber together do not mean you can move off. You must wait for green.
Common questions
What does red and amber mean at traffic lights?
It means stop. Know your traffic signs says you must not pass the stop line until green shows.
Does a green traffic light mean I can always go?
No. Know your traffic signs says you may go only if the way is clear, and must give way to pedestrians who are crossing.
Compare with
Amber traffic lightAmber means stop unless you cannot stop safely.
Green filter arrowGo only in the arrow’s direction, if clear.
Want to test someone else? Play a road-sign quiz with friends and family.
Sources
Checked on 5 November 2026 against Know your traffic signs (traffic signals) and The Highway Code rule 175.
Contains public sector information licensed under the Open Government Licence v3.0. The diagram is our own simplified drawing, not to scale. Sources and image credits.