Transport Secretary Geoff Hoon has said that he wants to install more average-speed cameras.
Hoon told The Times newspaper that many existing roadside cameras, which measure speed at a fixed point, could be replaced by the average-speed cameras. He believes average-speed cameras are fairer and encourage safer driving.
Average-speed cameras measure speed over distance and, at present, are usually found in roadworks on motorways.
Motoring organisation the AA warned that widespread use of average-speed cameras could lead to traffic bunching-up on busy roads as cars slowed all at once, but added that they are more effective than fixed place cameras.
AA research also suggests that average-speed cameras reduce the number of crashes, while penalising fewer drivers.