What is a smart motorway?

Smart motorways use technology to help control traffic flows, and therefore improve driver journeys. Features of smart motorways include:

Controlled motorways

Variable speed limits are displayed in a red ring overhead and are used when traffic volumes are high. These use monitoring sensors to activate lower speed limits and therefore ease congestion.

The red ‘x’

A red ‘x’ symbol on a gantry sign over the motorway indicates that a lane is closed due to an incident, or where people are working on the road.

You can find out more about non-emergency motorway problems here.

Hard shoulder running

On some motorways, the hard shoulder is opened as an extra lane at busy times and the speed limit is reduced.

Remember: Only use the hard shoulder when overhead signs show you that you can do so, or in an emergency.

Never driven on a motorway before? Take a look at our first time guide.

Find out more about the benefits of smart motorways in this video by Highways England:



Highways England’s ‘summer speed campaign’ aims to raise awareness of the new features of smart motorways. The campaign delivers these five messages:

  1. ‘Better watch your speed’ – you must stick to speed limits displayed in a red ring. When no speed limit is shown, the national speed limit of 70mph is in place.
  1. ‘On time journeys’ – speed limits vary at busy times to keep the traffic flowing and make journey times more reliable.
  1. ‘Be safe’ – millions use motorways every day so think about how the decisions you make affect others.
  1. ‘Don’t risk it’ – speed limits on smart motorways are enforced by police and if you break the speed limit you will be caught.
  1. ‘Respect our road workers’ – drive carefully and stay within the speed limit to help keep road workers safe.