Motorway Rules

Safe driving on motorways and high-speed roads.

At a glance

1
Keep in the left-hand lane unless you are overtaking, and return to it as soon as it is safe.
2
Overtake only on the right — but in congested, similar-speed traffic you may keep up with your own lane even if it passes vehicles on your right.
3
Traffic already on the motorway has priority: build up speed on the slip road and merge into a safe gap.
4
A red X above a lane means it is closed — you must not drive in it.
5
The hard shoulder is for emergencies or when directed onto it; it is a running lane only while a speed limit is displayed above it.
6
Stud colours: white between lanes, red on the left edge, amber by the central reservation, green at lay-bys and slip roads, green/yellow at road works.
7
Crawler lanes on steep hills are for any slow-moving vehicle — not only lorries.
8
In a contraflow expect narrower lanes: obey temporary limits and leave a bigger gap.
9
If you break down, aim for a service area or the next exit; otherwise use an emergency area or the hard shoulder.
10
70 mph is a car's motorway maximum — a limit, not a target; displayed lower limits always apply.
11
A car towing a caravan or trailer is limited to 60 mph on motorways.
12
Provisional car licence holders may only drive on a motorway with a DVSA Approved Driving Instructor, in a dual-controlled car showing red L plates (or D plates in Wales).

Motorway lane discipline

Keep in the left-hand lane unless you are overtaking, and move back to it as soon as it is safe once you have passed. The middle and right-hand lanes are overtaking lanes, not cruising lanes. Overtake only on the right, and never move to a lane on your left in order to overtake. In congested conditions, when adjacent lanes are moving at similar speeds, you may keep up with the traffic in your own lane even if this means passing vehicles in the lane to your right — but that is not a licence to weave left to overtake.

Unless a police or traffic officer directs you to, you must not reverse along any part of a motorway — including slip roads, hard shoulders and emergency areas — cross the central reservation, or drive against the flow of traffic.

Leave a gap of at least two seconds from the vehicle in front on high-speed roads. At least double that gap on wet roads, and leave one up to ten times greater on icy roads. Do not confuse the two measures: 96 metres is the Highway Code's typical total stopping distance at 70 mph, not a universal following-distance rule — the gap you follow at is measured in seconds, the stopping distance in metres.

Reflective road studs and their colours

Reflective road studs work alongside white lines. Learn to match each colour to its position on the road:

White: between lanes, or marking the middle of the road.
Red: along the left-hand edge of the carriageway.
Amber: along the edge by the central reservation of a motorway or dual carriageway.
Green: the edge of the main carriageway at lay-bys and slip roads.
Fluorescent green/yellow: temporary lane layouts, such as at road works.

Use the stud colour to identify which edge or boundary of the road you are looking at.

Joining and leaving a motorway

Traffic already on the motorway has priority. Use the slip road to build up your speed so you can merge into a safe gap in the left-hand lane, and do not force your way in. Once you have joined, stay in the left-hand lane until you have adjusted to the speed of the traffic around you.

Plan your exit in good time: move to the left-hand lane well before your junction and signal early. If you miss your exit, carry on to the next one — do not stop or reverse on the carriageway.

Provisional car licence holders must not drive on a motorway unless they are accompanied by a DVSA Approved Driving Instructor, in a car with dual controls that displays red L plates (or D plates in Wales).

Crawler lanes and contraflow systems

Crawler (climbing) lanes appear on some steep hills. Use one if you are driving a slow-moving vehicle, or if vehicles behind you want to overtake — they are not reserved for lorries. Watch for the signs and markings showing that the lane is about to end, so you can merge back in good time.

A contraflow at road works can put you in a narrower lane than usual, with no permanent barrier between you and oncoming traffic. Slow down and leave a larger gap as you enter and leave the contraflow, keep a safe distance from the vehicle in front throughout, and remember that you must not exceed a temporary maximum speed limit.

Hard shoulders, emergency areas and breakdowns

The hard shoulder is not a normal driving lane. You must not use it except in an emergency, or when police, traffic officers or signs direct you onto it. Where the signs above it display a speed limit, the hard shoulder is open as a running lane; if they do not, it is not a driving lane at all.

If your vehicle develops a problem, the order of preference is simple: pull into a service area if you can, or leave the motorway at the next exit. If neither is possible, move left and stop in an emergency area or on the hard shoulder. Get out by the side furthest from traffic if it is safe to do so, and wait well away from your vehicle and the carriageway — behind the safety barrier where there is one. Use the free emergency telephone where one is provided, or press your vehicle's SOS button if it has one. If you call from a mobile instead, the numbers and letters on marker posts and driver location signs tell the operator exactly where you are.

If you cannot get out safely — for example you are stopped in a live lane — stay in your vehicle and call 999 to ask for the police.

Rejoining matters as much as stopping: from a hard shoulder, build up speed, signal and join when there is a safe gap in the traffic; from an emergency area, you must use the emergency telephone first and follow the operator's advice for getting out.

Motorway signals and the red X

Overhead and roadside signals manage motorway traffic. Amber flashing lights warn of a hazard ahead — reduce your speed, and only speed up again once you pass a signal that is no longer flashing or one that ends the restriction. A red X above a lane means the lane is closed: you must not drive in it, and you should stay out of it until the signal ends or changes. On motorways where signs and signals manage lane use, follow every displayed lane closure and speed restriction, and always follow directions from police or traffic officers.

Speed limits shown inside a red circle are mandatory — you must not exceed them, whether they are permanent or variable.

Speed limits and temporary restrictions

The national speed limit for a car on a motorway is 70 mph. That is a maximum, not a target — in rain, fog, heavy traffic or road works, a safe speed is often much lower. Towing changes the class: a car towing a caravan or trailer is limited to 60 mph on a motorway.

Displayed limits take priority over the national limit: variable limits above the lanes, temporary limits at road works and any limit inside a red circle must all be obeyed. Always match the limit to the vehicle type — a car and a car towing a trailer have different maximums on the same road.

Official sources

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Contains public sector information licensed under the Open Government Licence v3.0. These summaries are for study purposes and do not replace the full Highway Code.