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What is a smart motorway?

  • Smart motorways are becoming increasingly common
  • How do they affect me when I'm driving?
  • Parkers gives you the low-down

Smart motorways (also known as actively managed motorways) vary the amount of lanes open and speed limit in order to improve road safety and maintain the flow of traffic.

How do smart motorways work?

There are three types of smart motorway. In each instance, electronic signs are positioned at various intervals on the carriageway displaying the variable speed limit (if there is one in place) and other traffic information.

Such signs will often be positioned above each individual lane, attached to an overhead gantry. This enables them to display individual instructions for each lane, such as whether it is open or closed. In the case of the latter, a red X will be shown to denote that the lane is closed.

Beware, driving in a lane with a red X above it is considered an offence, and anyone caught doing so could be fined £60 and receive three penalty points on their driving licence.

Note that smart motorways will often have speed cameras placed at intervals along the carriageway. These will be set to catch drivers exceeding the variable speed limit.

The three different types of smart motorway are as follows:

Controlled motorways have variable speed limits and a dedicated hard shoulder lane which is only for use in emergencies. Other lanes can still be closed by way of displaying a red X above.

Hard shoulder running motorways are self explanatory. The hard shoulder may be used as an extra lane during times of congestion with overhead signs displaying when it’s open to traffic. Generally, if the electronic sign above the hard shoulder is not illuminated with a variable speed limit, the lane is closed unless in an emergency.

All lanes running motorways have no dedicated hard shoulder, instead relying on emergency refuse areas positioned at around one-and-a-half-mile intervals. If you break down and are unable to make it to a refuse area, the lane you are in will be shut and a assistance will be sent to your location. Once again, the electronic signs will display variable speed limits and information on which lanes are open.

Where are the smart motorways located?

There is currently more than 236 miles of smart motorways dotted all over England, from the M1 in Bedfordshire, to the M4 in Somerset and M9 in Glasgow.

Looking for more jargon-busting motoring meanings? Head over to our Parkers Car Glossary page and take a look at our other definitions.