Traffic Lights

The Basics

Standard Light Sequence

In the UK, traffic lights follow a specific four-stage sequence. Knowing this helps you anticipate what happens next.

Red

STOP. Wait behind the stop line on the carriageway.

Red & Amber

GET READY. Prepare to move off, but do not cross the stop line yet.

Green

GO. Proceed if the way is clear and it is safe to do so.

Amber

STOP. Stop at the line unless you are too close to stop safely.

The Approach Routine

MSPSL Routine

Apply the Mirrors, Signal, Position, Speed, Look routine every time you approach traffic lights.

Mirrors

Check interior & side mirrors early.

Signal

Signal if turning left or right.

Position

Select correct lane early.

Speed

Adjust speed & gear progressively.

Look

Assess lights, traffic & safety.

Warning Signs

On high-speed roads or where visibility is restricted, you may see warning signs for traffic signals ahead.

Traffic Signals Ahead: A red triangle with a traffic light symbol warning of lights ahead.
Countdown Markers: On very fast roads, markers with 3, 2, and 1 stripes may precede the lights to help you gauge distance.

Professional Driving Skills

Mastering the Approach

Approaching traffic lights isn't just about stopping or going. It requires observation, anticipation, and a systematic routine. If the light has been green for a long time (a "stale green"), assume it will change and be ready to stop.

Filter Lights

Green Filter Arrows indicate you may proceed in the direction shown, even if the main light is red. Ensure the way is clear. If the arrow isn't lit but the main green is, you can turn but must give way to oncoming traffic (unprotected turn).

The MSM Routine

1
Mirrors Check interior and relevant side mirrors well in advance. Assess the speed and distance of following traffic.
2
Signal If turning left or right, signal in good time to warn other road users. Do not signal if going straight on.
3
Manoeuvre (Speed & Gear) Ease off the accelerator. Brake progressively. Select the appropriate gear for your speed. If stopping, aim to stop so you can see the tyres of the vehicle in front or the stop line.

Vulnerable Road Users

Advanced Stop Lines (Cycle Boxes)

Many urban traffic lights feature an area marked with a bicycle symbol between two stop lines. This is an Advanced Stop Line (ASL), designed to keep cyclists safe and visible.

Cycle Box

The Rules

Stop at the first line: Motorists must stop at the first white line when the light is amber or red.
Do not encroach: You must not drive into the marked area while the light is red.

Exceptions

Crossing on Amber: If the light changes to amber and you have already crossed the first line, do not stop abruptly in the box. Continue to the second line if safe, or clear the junction.
Safety First: Never block the cycle box if traffic is queuing. Wait behind the first line until there is space to clear the box.

Junction Rules

Lane Discipline & Priorities

Correct positioning is key to keeping traffic flowing safely. Here are the golden rules for lanes and roundabouts.

Left Lane for Straight On

When approaching a junction or roundabout with the intention of going straight ahead (usually the 2nd exit), the default rule is to use the left-hand lane.

Crucial Exception: Signs & Markings

Always scan for arrows on the road surface or road signs. If the left lane is marked "Left Turn Only", you must move to the next available lane designated for straight-on traffic.

Common Mistakes

Avoid these common errors during your test and daily driving.

Crossing on Amber

Accelerating to 'beat' the light when it turns amber. You must stop if safe.

Stopping Over the Line

Failing to stop behind the solid white line, encroaching on pedestrian crossings or the junction.

Ignoring Filter Lights

Waiting at a red light when a green filter arrow allows you to turn.