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
Author's Explanation
Light Signals Controlling Traffic Explained
Traffic light signals control the movement of vehicles and pedestrians to keep roads safe and organised. Drivers must understand each signal colour and react correctly, especially at busy junctions, crossings and high-speed roads.
A red light always means stop, while green allows drivers to continue only when the road ahead is clear and it is safe to proceed. Drivers must still give way to pedestrians when turning and remain aware of other road users.
Motorway signals and lane control signs provide warnings about hazards, speed restrictions and lane closures. A red X means a lane is closed, while green arrows show lanes that are available for traffic.
Real-Life Examples
Example 1: A driver approaches a red traffic light and stops behind the stop line until the signal changes.
Example 2: A driver sees an amber light and stops safely rather than accelerating through the junction.
Example 3: A motorway driver sees a red X above a lane and moves into another lane because the lane is closed.
Example 4: A driver follows a green arrow signal and turns only in the direction shown while checking that the route is clear.
Frequently Asked Questions
What does a red traffic light mean?
A red light means drivers must stop behind the stop line and wait until the signal changes.
Can you go through an amber light?
Drivers should stop at an amber light unless they have already crossed the stop line or stopping suddenly would cause an accident.
What does a red X motorway signal mean?
A red X means the lane is closed. Drivers must not use that lane and should move safely into an available lane.
What do green arrows on traffic lights mean?
A green arrow allows drivers to move only in the direction shown, provided the way is clear.