What is a smart motorway?
A smart motorway is a section of motorway where technology is used to manage traffic flow and increase capacity. There are three types, each with different rules about the hard shoulder.
The three types
Controlled motorways: have three or more lanes with variable speed limits displayed on overhead gantries. The hard shoulder is a traditional hard shoulder: for emergencies only. Signs will display a red X if a lane is closed.
Dynamic hard shoulder (DHS) motorways: the hard shoulder can be opened as a running lane during busy periods. A speed limit displayed above the hard shoulder means it is open to traffic. No sign or a red X means it is closed and for emergencies only.
All lane running (ALR) motorways: the hard shoulder has been permanently converted to a running lane. There is no hard shoulder at all. Instead, emergency refuge areas (ERAs) are positioned at intervals of roughly one mile.
Emergency refuge areas
On ALR motorways, if you break down or have an emergency, you need to reach an ERA if at all possible. These are marked with blue signs and an orange SOS phone. If you cannot reach an ERA, pull as far left as possible, put on your hazard lights, call 999, and if it is safe to leave the car, get over the barrier and stand well away from the carriageway. Do not stand on the motorway behind the vehicle.
Variable speed limits
Variable speed limits on smart motorways are mandatory, not advisory. A speed limit displayed in a red circle on an overhead gantry is a legal limit. Driving above it is an offence. Speed cameras are typically active on smart motorway sections. The cameras are there to enforce variable limits as well as the national motorway limit.
Red X signs
A red X displayed on a gantry above a lane means that lane is closed. Driving in a lane with a red X above it is a criminal offence since 2019. CCTV and cameras enforce this.
If you are on a motorway and have never driven on a smart motorway section before, Tomas's motorway lesson covers all of this in practice, with an experienced instructor alongside you.
