A comprehensive review of 'smart motorways' has been ordered after a ten fold increase in the number of motorists being fined while driving below 70mph.

There are currently more than 20 sections of smart motorways across the country, which are intended to ease congestion by monitoring the driving conditions and varying the speed limit where appropriate.

But many motorists have complained about being hit with fines for exceeding lower speed limits, even when the roads are relatively clear of traffic.

Highways England explained that lower speed limits were often set before the congestion built up in order to better manage the flow of traffic on some of the busiest roads.

But this has led to frustration among some drivers, who claim they are being forced to drive slowly along stretches of relatively deserted motorway.