Driving on 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. Do not use the size of your vehicle to force your way onto the motorway.
- Use the Mirrors – Signal – Manoeuvre/Position – Speed – Look (MSM/PSL) routine before you merge onto the motorway, looking out for motorcyclists in particular because they can be difficult to see.
- 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 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.
Use the MSM/PSL routine when you’re leaving the motorway to make sure you can do so safely, looking out particularly for motorcyclists who may filter between other vehicles or approach quickly behind you.
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, eg if your vehicle 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, eg 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 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.
Rules for driving on motorways and dual carriageways
Left-hand-drive vehicles
Motorways and dual carriageways are often used by large goods vehicles, particularly vehicles from other countries, which are usually left-hand drive. Remember that the drivers of these vehicles will be able to see less of the road and traffic around them: be careful not to drive too close to these vehicles.