In the tunnel
Keep in lane and do not overtake.
You must not drive in the right-hand lane in a motorway tunnel if you are driving a type of vehicle prohibited from using this lane, that is a HGV of more than 3,500 kilograms, a vehicle towing a trailer, horsebox or caravan, or a single or double deck bus or coach that is designed for carrying standing passengers.
Do not turn or reverse.
Do not stop, except in case of emergency.
Obey the speed limits. There are two forms of speed limit signs.
• a standard speed limit sign applies where there is a fixed speed limit. You must obey the speed limit and remember this is the maximum permitted speed, not the required speed.
• where the speed limit can vary, you will see variable message signs, which are black squares with red circles and numbers in white or yellow throughout the tunnel. The speed limit is shown by the numbers and will vary according to traffic conditions and road safety considerations. You must obey the speed limit and remember this is the maximum permitted speed, not the required speed. ‘Always remember the two-second rule.’
Keep your distance. The recommended minimum safe distance for a car
or motorcycle is 50 metres and for all other vehicles 100 metres.
Stopping
If you are instructed to stop, you should stop and: keep a safe distance between your vehicle and the vehicle in front; switch on your hazard warning lights; switch off your engine; check your radio for instructions from the tunnel operator; check all electronic signs in the tunnel for information; and if necessary, leave the tunnel using the nearest available pedestrian exit.