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Highway Code Multi-Lane Carriageway Rules

This section covers the driving rules and lane discipline on single carriageway and dual carriageways. The guide explains road furniture on multi lane carriageways in the United Kingdom.

MULTI LANE CARRIAGEWAY: There is extra guidance on how drivers should negotiate climbing and crawler lanes. Highway Code rules 133 to 143 also cover traffic flow in cycle and bus lanes, as well as one-way streets.

Highway Code Lane Discipline

Rule 133: Always use your car mirrors and take a quick sideways glance (where necessary) before changing lanes. This helps to ensure you will not force other road users to change their direction or their speed.

Signal to indicate your change of direction to other road users and move over when it is clear and safe to do so.

Rule 134: Motorists should follow the signs and road markings and move into the lane as directed. Even so, do not change lanes unnecessarily and especially in congested road conditions.

Merging in turn is the recommendation but only when it is safe to do so. It is most appropriate when vehicles are travelling at a very low speed.

An example could be as you approach road works or at a road traffic incident. But, merging into the traffic is not recommended at high speeds (e.g. while driving on motorways).

Single Carriageway with 3 Lanes

What is a single carriageway? As a rule, single carriageways are roads with only one lane for traffic travel in each direction. But, you can also find examples of a single dual carriageway with a middle lane. In this case, you are on a single carriageway with three lanes who may drive in the centre lane?

Rule 135: You may find a single carriageway with 3 lanes that is not a motorway. What if the road markings or signs do not give priority to traffic in either direction? In this case motorists should:

  • Use the middle lane only for overtaking or turning right.
  • Be aware that you have no more right to use the middle lane than a driver coming from the opposite direction.
  • Not use the lane on the right-hand side (applies to roads in Great Britain).

Rule 136: Use only the lanes that signs or markings show you can if a single carriageway has four or more lanes.

Highway Code Dual Carriageway Rules UK

The simple definition of a dual carriageway is a road which has a central reservation separating the two individual carriageways.

Rule 137: On a two-lane dual carriageway you should stay in the left-hand lane. But, use the right-hand lane for overtaking or turning right. After overtaking, move back to the left-hand lane when it is safe to do so.

Rule 138: On a three-lane dual carriageway, you may use the middle lane or the right-hand lane to overtake. But you should return to the middle, and then the left-hand lane, when it is safe.

Climbing and Crawler Lanes

Rule 139: As a rule, climbing and crawler lanes improve traffic flow on some of the steepest hills. So, use the climbing lane if you are driving a slow-moving vehicle or if there are vehicles behind you trying to overtake.

Note: Be aware of the signs and road markings which indicate when the climbing or crawler lane is about to end.

Cycle Lanes

Rule 140: Road traffic markings and signage identifies cycle lanes. You MUST NOT drive or park in a cycle lane marked by a solid white line during its times of operation.

Do not drive or park in cycling lanes if marked by a broken white line, unless doing so is absolutely unavoidable. You MUST NOT park in any cycle lane whilst its waiting restrictions apply and are in force.

Bus Lanes

Rule 141: Road signs state which other vehicles (if any) have permission to use the bus lane. Motorists should not drive in bus lanes during the period of operation.

Exceptions may apply if indicated otherwise. Where it is not prohibited, you may enter a bus lane to stop for loading or unloading purposes.

High-occupancy Lanes

Rule 142: High-occupancy vehicle (HOV) lanes and other designated vehicle lanes may have restrictions for use by particular types of vehicles. The restrictions may apply to certain periods or all the time.

The operating times and vehicle types will show on the accompanying traffic signs. You MUST NOT drive in such lanes during their times of operation unless signs indicate your type vehicle is permitted to do so.

The UK Highway Code rules also regulate whether certain vehicles have permission to use designated lanes. The restrictions may or may not include:

Where HOV lanes are in operation, they MUST ONLY be used by:

  • Vehicles containing at least the minimum number of people indicated on road traffic signs.
  • Any other vehicles, such as buses and motorcycles, as indicated on signs before the start of the lane. This is irrespective of the number of occupants in the vehicle.

One-way Streets

Rule 143: Traffic MUST always travel in the direction indicated by the signs of one-way streets. Even so, in some circumstances buses and cycles may have a separate contraflow lane. You should choose the correct lane for your exit from these contraflow lanes as soon as you can.

Avoid changing lanes without due warning to other road users. Traffic could be passing your vehicle on both sides. Unless the road signs or traffic markings show otherwise, motorists should:

  • Travel in the left-hand lane when going left.
  • Use the right-hand lane when going right.
  • Travel in the most appropriate lane when going straight ahead.

Multi Lane Carriageway and Dual Carriageway Rules in the United Kingdom