Light signals controlling traffic
Light signals used to control traffic, including traffic light signals, flashing red lights, motorway signals and lane control signals.
Traffic light signals
RED means ‘Stop’. Wait behind the stop line on the carriageway
RED AND AMBER also means ‘Stop’. Do not pass through or start until GREEN shows
GREEN means you may go on if the way is clear. Take special care if you intend to turn left or right and give way to pedestrians who are crossing
AMBER means ‘Stop’ at the stop line. You may go on only if the AMBER appears after you have crossed the stop line or are so close to it that to pull up might cause an accident
A GREEN ARROW may be provided in addition to the full green signal if movement in a certain direction is allowed before or after the full green phase. If the way is clear you may go but only in the direction shown by the arrow. You may do this whatever other lights may be showing. White light signals may be provided for trams
Flashing red lights
Alternately flashing red lights mean YOU MUST STOP
At level crossings, lifting bridges, airfields, fire stations, etc.
Motorway signals
These signals are also used on other high-speed roads.
You MUST NOT proceed further in this lane
Change lane
Reduced visibility ahead
Lane ahead closed
Temporary maximum speed advised and information message
You **MUST NOT** enter or proceed in the left lane, temporary mandatory maximum speed limit and information message
Temporary maximum speed advised
End of restriction
Lane control signals
Green arrow - lane available to traffic facing the sign
Red crosses - lane closed to traffic facing the sign
White diagonal arrow - change lanes in direction shown
Light Signals Controlling Traffic: What You Need to Know for the Theory Test
Traffic lights, flashing red signals, motorway signals and lane-control signals can change what you are allowed or required to do. The key is to recognise the signal and follow its specific meaning.
Stop at the stop line
A red traffic light means STOP. Wait behind the stop line and do not proceed until the signal permits you to go.
Still means stop
Red and amber together do not mean go. Remain stopped and wait for green before proceeding.
Go only if the way is clear
Green allows you to proceed when the way is clear. Take particular care when turning and give way to pedestrians who are crossing.
Stop unless stopping would be unsafe
Amber means stop at the stop line. You may continue only if the signal changes after you have crossed the line or stopping would create a risk of an accident.
Follow the arrow only
A green arrow permits movement only in the direction shown, provided the way is clear. The arrow can permit a movement separately from the full green phase.
You MUST stop
Alternately flashing red lights mean YOU MUST STOP. They are used at locations such as level crossings, lifting bridges, airfields and fire stations.
Obey the lane-specific message
Motorway signals can warn of reduced visibility, a closed lane, a required lane change, a temporary speed restriction or the need to leave at the next exit.
Never drive in the closed lane
A red cross means the lane is closed to traffic facing the signal. You MUST NOT proceed further in that lane.
Lane available
A green arrow above a lane means that lane is available to traffic facing the signal. Continue only when it is safe to do so.
Change lanes in the direction shown
A white diagonal arrow tells you to change lanes in the direction indicated. Make the change safely and without waiting until the last moment.
React to the message, not just the colour
On motorways and high-speed roads, look at the complete signal. A lane-specific symbol can impose a different instruction from the general traffic conditions.
Which signal is the common trap?
Remember the critical distinctions: red = stop, red + amber = still stop, amber = normally stop, red cross = lane closed, green arrow = lane available.
Remember Before the Theory Test
Don't Mix These Up on the Theory Test
Traffic signals contain several combinations that look similar but have very different meanings.
Light Signals Controlling Traffic: Theory Test FAQ
What does a red traffic light mean?
Red means stop. Wait behind the stop line on the carriageway and do not proceed until the signal permits movement.
What does red and amber mean at traffic lights?
Red and amber together still mean stop. Do not start moving until green appears.
What should you do when the traffic light turns amber?
You should normally stop at the stop line. You may continue if the amber appears after you have crossed the line or you are so close that stopping could cause an accident.
Can you turn when the traffic light is green?
Yes, if the way is clear and the movement is permitted. When turning, take special care and give way to pedestrians who are crossing.
What does a green arrow at traffic lights mean?
A green arrow permits movement in the direction shown by the arrow, provided the way is clear. It can allow that movement even when other traffic signals are showing different indications.
What do flashing red lights mean?
Alternately flashing red lights mean YOU MUST STOP. They can be used at locations including level crossings, lifting bridges, airfields and fire stations.
What does a red cross mean on a motorway?
A red cross means the lane is closed to traffic facing the signal. You MUST NOT proceed further in that lane.
What does a green arrow above a motorway lane mean?
A green arrow means the lane is available to traffic facing the signal. Continue to drive safely and follow any other applicable signs and markings.
What does a white diagonal arrow mean on a motorway?
It tells drivers to change lanes in the direction shown. The lane change should be made safely and in good time.
What do motorway signals warn drivers about?
They can communicate lane closures, required lane changes, reduced visibility, temporary speed restrictions, information messages and instructions such as leaving the motorway at the next exit.
What is the most important traffic-light rule to remember for the Theory Test?
Do not memorise colours in isolation. Remember the key actions: red means stop, red and amber still means stop, amber normally means stop, green permits movement when safe, and a red cross closes a lane.