As you learn the rules of the road, it’s natural to get hung up studying some of the more obscure road signs and symbols. But don’t neglect the common ones, because they’re equally important, and just as likely to trip you up. Take traffic lights: we see them so frequently that it’s easy to take for granted that we know what they mean. But for your theory and practical tests, a general idea just won’t cut it.
Traffic lights play a vital role in controlling traffic flow and preventing accidents, and to do that effectively they need to be properly understood. To help you on your way, we’ll take you each phase of the full traffic light sequence, including flashing amber lights. We’ll also explain green filter arrows and why you shouldn’t move through a red light—even for an emergency vehicle. All you need to do is read, imbibe and put this guide into action.
Understanding the traffic light sequence
First thing’s first: you need to know the order in which a traffic light lights up. The basic sequence contains four phases, and each has a separate meaning.
Red and Amber (Prepare to pull away)
or Flashing Amber (give way to pedestrians; go if it’s safe to do so)
Amber (Stop unless it’s not safe to do so)
It sounds simple—and it is. But let’s delve a bit deeper into the rules so that you won’t get caught out on the roads.
Stopping at a red light
In driving, the colour red means you’re prohibited from doing something. So, when faced with a red traffic light, you aren’t allowed to go through it. Simply put: stop!
It’s a serious offence to run a red light, because it puts you and other road users at risk. Some junctions therefore use traffic cameras to catch people jumping the lights; those caught can be issued a fine and risk points on their licence.
When approaching a red traffic light, you should follow all the usual rules for pulling up. Check your mirrors, brake in good time and leave enough room behind the vehicle in front. Once stopped, you can put the handbrake on, move the gear stick into the neutral position and remove your feet from the pedals. That’ll give your feet a rest, and stop you worrying about the car rolling or stalling.
When you’re sitting stationary at a red light, keep your wits about you. It’s never a good idea to start applying make up, and it’s downright illegal to pick up your phone.
Where should I stop?
Traffic lights are accompanied by a solid white line marked on the road, to show you where you need to stop. No part of your vehicle is allowed to cross the line at a red traffic light. Sometimes there will be an area in front of you designated for cyclists. It’s important that you keep this clear, because cyclists are vulnerable road users: allowing them to the front of the queue at junctions helps to keep them safe.
✓ Always stop behind the solid white line at a red traffic light
✓ Put your handbrake on and take the car out of gear
✗ Don’t get distracted when you’ve stopped
Red and amber lights: preparing to go
After red, traffic lights turn red and amber. This means that you should prepare to go, but crucially, you should not pull off. The red light is still on, and the red light means stop. So, no creeping forwards and absolutely no crossing the white line marking on the road. Moving away at this point makes you into a hazard for other road users.
So that there are no unnecessary delays, you can prepare for the green ‘go’ light by putting the car in gear. As you’re about to complete a manoeuvre—pulling away—you can also start performing your observation checks. Look in all 3 mirrors and make sure you’re aware of any cyclists also waiting at the junction.
Keep your car still by keeping your handbrake on, and slowly releasing the clutch pedal to find your biting point.
✗ Don’t start creeping forwards when the red and amber lights are on
✓ Check your mirrors
✓ Put your car in gear and prepare to move off by finding your bite point
Flashing amber traffic lights
Traffic lights at some pelican crossings (the ones with red and green men) have a slightly different traffic light sequence. Rather than turning red and amber, they use a flashing amber light to indicate that drivers can go if it’s safe to do so.
Shortly after a pedestrian presses the button, the traffic light will turn red, stopping all traffic. The green man will appear, allowing them to cross safely. After the green man has turned back to red, the traffic light will display a flashing amber light to signal to drivers that they may start moving, if their path is clear.
Pedestrians crossing the road still have priority at this point. Although people shouldn’t really start crossing on a flashing amber, it gives those already en route a bit of extra time to get to the other side. If—and only if—there are no pedestrians crossing, you may go through the flashing amber traffic lights.
✓ As you approach a pelican crossing, look out for pedestrians who may be about to press the button
✓ When the traffic light changes to flashing amber, check there are no pedestrians still crossing the road
✓ Check your mirrors before moving away
Pulling away at a green light
Green is for go: when the red and amber lights turn off and the green light is illuminated, you can start to pull off. If there are vehicles in front of you, keep an eye on them as well as the traffic lights. It’s no good moving forwards if the car in front hasn’t started yet, because you’ll just crash into the back of them.
If you’re at a junction with a pedestrian crossing, check that there is nobody still in the road or about to step out onto it. And if traffic is blocking your path, it’s safest to stay behind the white line until the road ahead is clear.
When you can, release your handbrake and pull away—and remember, there’s no need to rush. Flooring your accelerator is bad driving and bad for your car.
✓ Watch out for cyclists and other vulnerable road users
✓ Make sure your vehicle is in gear and you’ve found your biting point, then release your handbrake
✓ Off you go!
What should you do at a steady amber light?
Next up in the traffic light sequence is a steady amber light, which means you should stop unless it’s not safe to do so. According to the Highway Code, the only exceptions to stopping at an amber traffic light are:
- If you’ve already crossed the white line at the junction, or
- If you’re so close to the line that stopping would cause an accident.
You’re obviously responsible for making the final judgement call on the roads, and it’s a decision you’ll have to make quickly. What’s clear, though, is that an amber light is not a cue to start speeding up. So our top tip for approaching a traffic light is that you should always anticipate it changing. In practical terms that means you should:
- Check your mirrors in preparation, so that you’re aware of road users behind you
- Make sure you’re not tailing another motorist too closely, so that if they slam on the brakes, you can respond in time.
✓ Stop at the amber traffic light unless you’ve already crossed the white line or it’s not safe to do so
✓ When approaching a green traffic light, always anticipate that it might turn to amber
✓ Be aware of other road users around you
Green filter arrow
Sometimes traffic lights have a green arrow light, known as a filter, as well as (or instead of) the normal green light. When a green arrow is lit up, you may move in the direction it indicates, regardless of any other lights showing at that junction.
On your driving test, the examiner will expect you to be aware of filter arrows, just like any other traffic light signal. If you don’t obey a filter light and this impedes other drivers, you will receive a major fault and fail the test.
Turning right at a filter arrow
Traffic light filters are commonly used where there is a right turn at the junction. Turning right leads you across the path of traffic travelling in the opposite direction, so they are generally more risky than left turns. When the normal green light is showing, you can move a little way forwards, but cannot make your turn unless your path is clear; vehicles on the other side of the road have right of way.
When the filter arrow is on you can drive cross the junction safely, because traffic coming from other directions is stopped by red lights. Keep your eyes open for arrows, because they may light up before or after the normal green light phase. You still need to be vigilant as you drive through the lights, particularly watching out for pedestrians and cyclists.
✓ Look out for filter arrows at any traffic lights you come across
✓ The filter arrow overrides other lights signals showing
① What if I run a red light by accident?
Driving through a red light is a strict liability offence: if you do it, even unintentionally, you are guilty. If you’re caught, the only way to avoid getting penalised is to prove that you didn’t run the light or that the camera wasn’t working properly. You might be able to appeal on the grounds of mitigating circumstances, but you are unlikely to win if the court has photographic evidence of you.
② If an emergency vehicle comes up behind me at a red traffic light, can I move forwards out of the way?
When it comes to getting out the way of emergency vehicles using sirens or flashing lights, rule 119 of the Highway Code says that you should:
take appropriate action to let it pass, while complying with all traffic signs.
Clearly, that means you still have to adhere to traffic lights, and you can get penalised for not doing so. Driving through a red light—whatever the circumstances—is likely to put you and other road users in danger. So sit tight, wait for the lights to change, and then act appropriately to let the emergency vehicle pass.
③ What do I do at temporary traffic lights?
Where there are roadworks, temporary traffic lights might be used to control the traffic. They work just the same as normal traffic lights, although you will usually be asked to stop level with a sign, rather than at road markings.
Some other traffic lights are permanent features, but a sign will indicate that the lights are turned off during quieter times of day. When no signal is showing, you can pass through them as normal.
④ What if the traffic lights aren’t working?
Sometimes there might be a sign indicating that the lights are out of order, but you may just have to find it out for yourself. If traffic lights are broken, nobody has priority. In this instance, approach the junction like a bit like you would an unmarked crossroad. Look for traffic coming from every direction before entering the junction, then once you’ve seen that it’s safe, proceed with caution.
⑤ What should I do if someone honks me at a traffic light?
If you’re waiting at a traffic light, and another driver honks their horn, always check the light signals for yourself before pulling off indiscriminately. Perhaps you haven’t seen that the lights have changed to green. Or maybe there’s a filter arrow has lit up, indicating that your lane can go. But it’s also possible that the driver got it wrong, or was honking to warn a different road user of a hazard.
It’s not just red lights you must stop for. You also have to follow signals from certain authorised persons, including the police. And, now that you’ve got the traffic light sequence down to a tee, why not check out our other guides—like this one on common motorway signs.