At a UK traffic-light-controlled junction, you are stopped at a red light. Which sequence correctly describes what the lights show, in order, from this point until they next return to red, and what should you do when you see the red-and-amber combination?
- Red changes straight to green, then to amber, then back to red; there is no combined phase
- Red changes to a flashing amber phase during which you may proceed if the way is clear, then green, then straight back to red
- Red changes to red and amber shown together, meaning you must continue to wait and not move off yet, then green, then amber, then back to red
- Red changes to green immediately once a vehicle is detected by a sensor, skipping any amber phase entirely, then straight back to red
Why C? And why not the others?
Correct answer: C. Red changes to red and amber shown together, meaning you must continue to wait and not move off yet, then green, then amber, then back to red
The standard UK traffic light sequence at a light-controlled junction runs red, then red and amber displayed together, then green, then amber, then back to red; the red-and-amber combination specifically means a driver must continue to wait exactly as they would at a plain red light, since it is a get-ready signal rather than a go signal, and moving off during it is not permitted. Describing the sequence as jumping straight from red to green with no combined phase is wrong, since the red-and-amber stage is a standard and universal part of the cycle at these junctions. Describing a flashing amber phase during which a driver may proceed is wrong because that phase belongs to a completely different type of signal, the pelican pedestrian crossing, not an ordinary junction traffic light, which has no flashing phase of its own. Claiming green appears immediately once a sensor detects a vehicle, skipping amber entirely, is also incorrect, since even where sensors control the timing of when a light changes, the fixed order of the phases themselves, including the red-and-amber and closing amber stages, does not change or get skipped.
Source: The Highway Code, Rule 175 (light signals controlling traffic, GOV.UK)