Average speed cameras could be fitted on all of Britain’s motorways if new proposals are approved by the Government.

In a recent report the governement agency predicted that if all drivers stuck to 70mph, the UK’s carbon emissions would be cut by 1.4 million tonnes.

The Sustainable Development Commission argued against traditional speed cameras saying that drivers slam on the brakes as they approach and then speed off after.  Average speed cameras encourage more smoother driving, which, it argues is more environmentally friendly.

The average speed camera devices lead to fewer accidents and speeding tickets on the roads where they are installed than normal speed cameras, a new report by the Government’s environmental advisers claims.

The government is looking to extend this beyond motorways with a new generation of cameras that can track journeys over a network of streets. This could mean speed cameras being fitted on all residential roads with a speed limit of 20 mph.

Quite how this would work in practice is unclear. The average speed cameras work by calculating the distance travelled and the time taken, arriving at an average speed. It is rare indeed to be able to drive at anything approaching the speed limit on Britains crowded urban streets.

We may not have the choice of speed soon as the report goes further, suggesting capping all cars to make it impossible to break the speed limit. Given that the courts sometimes accept special reasons for speeding such as an emergency this would be an interesting development