Traffic light sequences and vehicle light signals form one of the most predictable parts of the theory test, since the meanings are fixed and don't vary by location. This section covers the standard traffic light sequence, filter arrows, and what different vehicle lights, such as headlight flashes or hazard warning lights, are meant to communicate.
Because the rules here are precise rather than a matter of judgement, this is an area where learners should be scoring full marks in mock tests, and any mistakes usually come down to not learning the exact sequence rather than genuine ambiguity in the rules.
The standard traffic light sequence
The sequence runs red, then red and amber together, then green, then amber, then back to red. Red and amber together means prepare to move but you must not go yet, and amber alone means stop unless you're so close that stopping would be dangerous, not an invitation to speed through.
Filter arrows and additional signals
A green arrow allows movement in the direction shown even if the main light is red, but only in that specific direction, and a green light generally means go if the way is clear, not an automatic right to proceed regardless of other hazards. Some junctions also use a flashing amber light for pedestrian crossings integrated into the light sequence, which was covered under pedestrians.
Vehicle light signals
Flashing headlights should only be used to let another road user know you're there, not as a substitute for right of way or to wave someone through, since its meaning under the Highway Code is limited to that single purpose. Hazard warning lights should be used to warn of a temporary obstruction, such as a breakdown, and not as a way to say thank you or as parking lights on a normal street.
- Flashing headlights = 'I am here', nothing more.
- One flash of the horn can carry the same limited meaning as headlights in daylight.
- Hazard lights = warning of a temporary obstruction or hazard, or briefly to warn traffic behind of a sudden slowdown on a motorway.
Reading the whole junction, not just the lights
Even with a green light, you should check the junction is genuinely clear, since another vehicle may still be clearing the junction from a previous phase or a pedestrian may be finishing a crossing. Never treat a green light as a guarantee that no hazard remains.
Frequently asked questions
What does red and amber showing together at traffic lights mean?
It means the lights are about to change to green, so you should prepare to move, but you must not go yet. Moving off during this phase is treated the same as jumping a red light.
Can I proceed on an amber light?
You should stop unless you've already crossed the stop line or are so close to it that stopping suddenly would be dangerous. Amber is not a signal to speed up and get through before red.
What does a green filter arrow mean?
It allows you to proceed in the direction the arrow points even if the main light facing you is red, but only in that direction. It doesn't apply to any other lane or movement.
What is the correct meaning of flashing your headlights at another driver?
It only means you are letting them know you are there. It should never be used to wave someone through a junction or claim priority, since the other driver could misread it as something else.
When should I use hazard warning lights?
To warn other road users of a temporary obstruction, such as your vehicle breaking down, or briefly to alert traffic behind you to a sudden hazard ahead on a fast road. They shouldn't be used routinely for parking or as a substitute for indicating.