Lesson 11 of 18 · Road skills

Traffic lights and box junctions: step by step

What each light means, what to do on amber, how to turn right at lights, and when you may enter a yellow box. Each step matches the numbers on the pictures, and there is a quiz at the end.

Fifth on DVSA's list of reasons learners fail is Not responding appropriately to traffic lights: going on red, stopping at green when it was clear, or waiting in the wrong place. DVSA's top 10 reasons for failing.

What the lights mean · Amber · Cyclists' boxes · Turning right · Filter arrows · Box junctions · Quiz

What the lights mean

Always in this order: red, red and amber, green, amber, then red again.

Red

RED means 'Stop'. Wait behind the stop line on the carriageway

Red and amber

RED AND AMBER also means 'Stop'. Do not pass through or start until GREEN shows

Green

GREEN means you may go on if the way is clear.

Amber

AMBER means 'Stop' at the stop line.

Green is permission, not an order: give way to people still crossing, and take special care turning left or right. The Highway Code: light signals.

Amber: stop or go?

The Highway Code's rule is short: If the amber light appears you may go on only if you have already crossed the stop line or are so close to it that to stop might cause a collision.

A light that has been green for a while may change at any moment. Ease off and cover the brake as you approach, so you are never caught too close to stop.
Check your mirror as you approach, so you know whether a hard stop would be safe.
Never speed up to beat the change.

The Highway Code, rules 175 and 176.

A junction with traffic lights, from above. Your car waits at red behind the first white stop line. Between that line and a second one nearer the junction is a box painted with a bicycle, where a cyclist waits.

Cyclists' boxes: the first white line

Some lights have two stop lines with a bicycle painted between them, so cyclists can wait ahead of the traffic, where you can see them.

At amber or red, stop at the first line. Keep out of the box.
Over the first line when it turns red? Stop as soon as you can, and at the second line at the latest.
On green, give the cyclists time and room to move off first.

Drivers MUST stop at the first white line reached if the lights are amber or red. The Highway Code, rule 178.

A junction with traffic lights, from above. Your car waits at red at the first white line, signalling right. On green it moves forward to the point of turn in the middle of the junction and waits while oncoming cars go straight past. When the lights change to red and the oncoming traffic stops, it finishes the turn into the road on the right.

Turning right at traffic lights

Red: wait at the first white line
Signal right and position just left of the middle of your lane, as for any right turn. Stop at the first line, out of the cyclists' box.
Green: forward to the point of turn, if it is clear
Move forward into the junction to where the middle of your road meets the middle of the new one, wheels straight. Only if there is room for you.
Wait there for a safe gap
Oncoming traffic going straight on has priority. Wait at the point of turn, not back at the line, so you do not hold up the traffic behind.
When the lights change, finish the turn
You are already past the line, so when the lights go red and oncoming traffic stops, check it really has stopped, then complete the turn.
Into the left of the new road
Look out for people crossing the road you are turning into, and for anyone running the red.

The Highway Code: Only go forward when the traffic lights are green if there is room for you to clear the junction safely or you are taking up a position to turn right. Rule 176.

Filter arrows and lanes

A green arrow can light up beside the main lights. If the way is clear you may go but only in the direction shown by the arrow. It applies whatever the other lights are showing.

Read the lane arrows early. Painted arrows and signs show which lane goes where. Get into the right one in good time.
A filter lane is only for traffic going that way. Do not use it to get past the queue.
Leave room for others, especially cyclists, to get into the right lane.

For a filter lane: Do not enter that lane unless you want to go in the direction of the arrow. The Highway Code, rule 177.

A junction from above with yellow criss-cross lines over the middle. The road you want is queued back to the box, so your car waits at the stop line. A faded car stopped inside the box is crossed out.

Yellow box junctions

The yellow criss-cross lines keep the middle of a busy junction clear, so traffic crossing your path is never blocked.

Do not enter until your exit is clear, even on green. If the road you want is queued back to the box, wait at your line.
The exception: turning right, you may wait in the box if only oncoming traffic, or others waiting to turn right, stops you.

You MUST NOT enter the box until your exit road or lane is clear. The Highway Code, rule 174.

When the lights are not working

Lights that are out, or stuck, give nobody priority. Treat the junction as an unmarked one: slow right down, look all ways, and only go when you are sure it is safe. If a police officer or traffic officer is directing traffic, follow their signals instead.

If the lights are not working, treat the situation as you would an unmarked junction. See unmarked crossroads.

Traffic lights quiz

Ready when you are

10 questions
About 3 minutes
Answers explained
Nothing saved

The plans from above are drawn for this page. The Highway Code on junctions, rules 170 to 183.

Questions people ask

Can you go through on amber?

Only if you have already crossed the stop line when it turns amber, or you are so close that stopping might cause a collision. Otherwise amber means stop.

What if I am over the first line of the cyclists' box when the light turns red?

Stop as soon as you can, and at the second line at the latest. Then give the cyclists time and room to move off when it turns green.

Can you wait in a yellow box junction to turn right?

Yes, if your exit is clear and you are only held up by oncoming traffic, or by others waiting to turn right. Otherwise do not enter the box until your exit is clear.

What do you do if traffic lights are not working?

Treat the junction as an unmarked one, where nobody has priority. Slow right down, look all ways, and only go when it is safe.

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Lesson 11 of 18 · Road skills

Traffic lights and box junctions: step by step

What the lights mean