HOW SMART MOTORWAYS AIM TO OPERATE...

Hard shoulders: Smart motorways seek to increase road capacity without costly and lengthy widening roadworks. One way they aim to achieve this is to temporarily open the existing hard shoulder to all traffic, shown by a speed limit sign above the lane – but no digital information display above the road means normal hard shoulder rules still apply.

Speed limits: Smart motorways use variable speed limits – displayed on the overhead gantries at regular intervals – to manage congestion during busy periods and if there is an accident or obstruction. Drivers must follow the digital signs displaying the maximum speed allowed in red circles, or be fined for speeding.

The usual national speed limit of 70mph only applies on smart motorways if an alternative number is not shown.

Lane closures: A red ‘X’ displayed above a lane indicates it is closed and drivers must always exit this lane as soon as it is safe to do so.

Emergency breakdown: Drivers experiencing an emergency themselves on a smart motorway, such as a breakdown, should try to leave at the next junction, or if that’s impossible move to the nearest safe space.

If the hard shoulder is being used by regular traffic, then such safety can be sought in emergency refuge areas (ERAS) that are spread out along the motorway. These look like small lay-bys and contain an orange SOS telephone.

Vehicles unable to reach an

ERA should move as close to the nearside (left hand) verge as possible. Drivers need to remember, in all cases, to turn on the hazard warning lights and only exit the vehicle, to seek shelter behind the safety barrier, if it is safe to do so.

Those who remain stuck in their vehicles on the carriageway should stay belted-up and ring 999 on their mobile phone, so the police can instruct the regional traffic control centre to close the necessary lanes.