Traffic officer's signal, a green light and an ambulance
You are the first vehicle at a signalised junction and your light is green. In the middle of the junction a Traffic Police officer is standing facing your direction of travel with his right arm raised vertically, palm towards you. Behind you, an ambulance is approaching with flashing lights and siren, about 30 m back in your lane, and the queue behind you is tight. In the lane on your right, a car has begun to edge forward. Across the junction, traffic from the left is starting to move.
1. Which instruction governs you: the green light, the officer's raised arm, or the ambulance behind?
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The officer. A police officer directing traffic overrides the traffic lights, signs and road markings. The green light tells you the signals permit you to proceed; the officer is personally directing the junction and his instruction supersedes that permission.
This is not a technicality - it is the safer source of information. He can see the ambulance behind you and the cross traffic on your left; the signal head cannot.
The ambulance gives you no right to move. Flashing lights and a siren are a request for priority, not an instruction that overrides a police direction. It is likely the officer has stopped your direction precisely so that ambulance, or the cross traffic, can clear.
So: stay stopped, foot on the brake, handbrake on if the wait looks long.
2. What should you do about the ambulance behind you, and what must you avoid?
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Open a path only within what the officer's signal and the junction layout allow.
Acceptable: if there is room to ease forward or to the left without crossing the stop line into the junction or onto the pedestrian crossing, do it slowly and deliberately so the officer and the ambulance driver can both see your intention. Align the car rather than driving anywhere.
Avoid:
- Proceeding into the junction against the officer's signal - that would be a red-light-style offence and could put you into the path of the cross traffic now moving from your left.
- Mounting the kerb or reversing into the queue.
- Waving the ambulance through. You cannot see what the officer can, and a well-meant gesture can send it into a collision.
3. The car on your right starts to move forward. What do you do?
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Do nothing. Another driver's mistake is not an instruction, and copying it is how two vehicles end up in the middle of a junction at once.
Traffic from the left has just begun to move, so anyone entering the junction now is entering the path of cross traffic. Let the car on your right make its own error; it does not make the route safe for you.
Instead:
- Hold position and keep watching the officer for the next change of signal.
- Move off only when he releases you, and then re-check the junction yourself before proceeding rather than following the car on your right.
- If the other car's move has created an obvious collision risk, a short horn warning is appropriate.