Motorways and dual carriageways
Motorways and dual carriageways allow traffic to travel faster and in greater safety than on ordinary roads, but it’s vital to know the rules that apply on them.
Joining a motorway or dual carriageway
Slip roads allow you to join a motorway or dual carriageway.
- Use the slip road to accelerate until your speed matches that of the traffic on the motorway.
- Check there’s a suitable gap in the left-hand lane.
- Use the Mirrors – Signal – Manoeuvre/Position – Speed – Look (MSM/PSL) routine before you merge onto the motorway.
- You must give priority to traffic already on the motorway: do not force your way into the traffic stream.
- Avoid stopping at the end of the slip road unless you’re queuing to join slow-moving traffic.
Leaving a motorway or dual carriageway
Slip roads also allow you to leave a motorway or dual carriageway. You’ll need to be in the left-hand lane so that you can drive onto the slip road when you reach it. Move into the left-hand lane in good time to make sure you do not have to cut in front of other vehicles or miss your exit.
Road signs and markers will help to warn you when you’re approaching your exit: use these to get into the correct position.
If you’ve been driving at motorway speeds for some time, when you leave the motorway your judgement of speed is likely to be affected: 40 or 45 mph will feel more like 20 mph. Check your speedometer and make sure you adjust your speed for whatever is on the road ahead of you.
Stopping on a motorway
You must not stop on a motorway unless
- red lights or other signs or signals tell you to
- you’re asked to stop by the police, National Highways traffic officers or DVSA officers
- it’s an emergency
- it will prevent an accident.
You must not
- stop to pick up or set down anyone on any part of the motorway, including a slip road
- walk on the motorway, except in an emergency.
Only use the hard shoulder in an emergency; for example, if your car breaks down.
If you have to slow right down or stop because there’s serious congestion ahead, you can use your hazard warning lights briefly to alert drivers behind you. Remember to turn them off when the driver behind you has slowed down.
Lane discipline
You should normally drive in the left-hand lane: avoid changing lanes unnecessarily.
The central reservation is there to separate the traffic flowing in different directions. Never drive across the central reservation or drive against the flow of traffic on a motorway or dual carriageway unless you’re directed to do so by an authorised person or traffic signs; for example, in roadworks.
Active traffic management (ATM, also called ‘managed motorways’) is used on some stretches of motorway to change speed limits or the direction of flow in particular lanes: make sure you obey any instructions given by these systems.
When you’re driving towards a junction, it’s important to scan well ahead to make sure that you’re aware of
- other road users joining or leaving the motorway: you may need to change lanes, if you can do so safely, to keep travelling at a steady speed
- queuing traffic.