The Department for Transport (DfT) is planning to introduce average speed cameras on 500 miles of motorway, in order to ensure drivers constantly obey speed limits.
The move comes because of rising concerns that drivers know they are unlikely to be prosecuted at speeds of up to 85mph on motorways. Research also shows drivers rarely obey variable speed limits and frequently learn the position of speed cameras and slow down specifically for them.
The DfT hopes that introducing average speed cameras over wider areas will force drivers to obey speed limits at all times.
Average speed cameras use numberplate recognition to record the time it takes a driver to travel between any two points and work out the average speed.
At present the Highways Agency uses average speed cameras only on motorways where there are contraflows during roadworks.
The introduction of average speed cameras across Britain's motorways could begin within 12 months.