Smart motorways were introduced as a form of traffic management to increase capacity on the roads by using variable speed limits and opening the hard shoulder during busy times.
However, in the light of recent tragic accidents and fatalities, their safety for ordinary road users have come into question.
Giving evidence to the House of Commons Select Committee, the head of the Highways England told them so-called "dynamic" smart motorways, where the hard shoulder is used as a live lane during peak times, are "too complicated for people to use" and that the system would not be extended to other roads.
These Smart motorways were designed so that capacity could be increased and congestion reduced, rather than going to the expense of widening roads.
The "dynamic" design is in use on sections of the M1, M4, M5, M6, M42 and M62 accounting for 68 miles in all. However, there is 135 miles of the "all lane running" system, with its emergency refuge areas. There are also "controlled motorways" - which have variable speed limits and can be found on around 120 miles of motorway.
To use these motorways properly, be prepared and research your journey beforehand to check whether you will encounter any Smart sections. Ensure your vehicle is roadworthy and has enough fuel. If you suspect any mechanical concerns, do not drive it and contact MotorEasy.
Always pay close attention to the overhead gantries and make sure that you can see any variable speed limits. If you spot a large red cross, you should not enter the indicated lane.