Smart Motorways

Smart Motorways

Introduced around the country since 2006, smart motorways are monitored by regional control centres that use technology to control the flow of traffic, changing signs and speed limits to keep things flowing freely. They increase road capacity by temporarily or permanently opening the hard shoulder to traffic.

The rules and advice for driving on them differs a little from conventional motorways, so it’s worth taking some time to familiarise yourself with possible signage, laws and emergency procedures. There are 3 types of smart motorway currently in operation:

  • Controlled motorway – multiple lanes, variable speed limits and a hard shoulder for use in emergencies only.  (western section of M25)
  • Hard shoulder running – variable speed limits and a hard shoulder that can be opened as a running lane at busy times. Overhead signs tell you when you may drive on the ‘hard shoulder’ (M42 J7-9, M4 J19-20, M5 J15-17).
  • All lanes running – variable speed limits, no hard shoulder, and emergency refuge areas every 2.5km. (M25 J23-27, M25 J5-6/7). This is the standard for all new schemes since 2013.

Speed Limits

Variable speed limits normally appear on overhead gantries, designed to help traffic flow smoothly and prevent “stop-start” driving, or to respond to an incident. If nothing is displayed, then the national limit applies. However, a speed limit displayed inside a red circle is legally enforceable. Speed cameras operate across all lanes, and may also work on an average speed basis. Always keep to the limit displayed for safety reasons. If not, you are likely to receive a fine and points on your license – for more information on new speed laws, visit our webpage.

Hard Shoulder Use

Hard Shoulder Running or All Lanes Running motorway schemes mean that traffic can drive on the hard shoulder part or full time. Where the lane has been permanently converted, it will look like any other lane, with a broken white line. Where it is temporary, the solid white line will still be in place. Check the gantry signs to see which lanes are open. A red cross will indicate a closure. For your own safety, and for that of other road users, you must not use that lane under any circumstances and will be fined for doing so.

In An Emergency

All Lanes Running motorways have Emergency Refuge Areas (ERAs) spaced every 2.5km. These are small laybys for use in breakdowns and emergencies, marked by blue signs with an orange SOS phone symbol. Make your way to the nearest one, put on your hazard lights, and use the emergency phone to contact the traffic control centre, who will send a traffic officer to assist you. When you need to rejoin the motorway, they will reset the signs to allow you to build up speed, as the ERA is too short for you to do this.

If you are unable to reach an ERA, put on your hazard lights and move your vehicle as close to the verge or nearside boundary as possible. Exit your vehicle through the passenger door if safe to do so. Either walk to the nearest emergency phone, well away from the carriageway, or dial 999 on your mobile. See our Breakdown & Emergency page for further advice, and what to carry in your car.

Remember that prevention is better than cure. Breaking down on any motorway is a stressful experience. Always make sure your car is in good condition before you set off. Check tyres, oil and water, and make sure you have sufficient fuel for your journey. 



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