Deaths and injuries caused by road accidents would be significantly reduced with the introduction of 'Intelligent Speed Adaptation' (ISA) claims the Institute of Advanced Motorists (IAM).

ISA is a system which allows vehicles to know the recommended speed limit for roads. It uses the global satellite positioning (GPS) and a digital road map to identify the speed limit of the road which the vehicle is travelling on.

The ISA system has three levels at which it could operate: -

Advisory - the driver is informed of the speed limit and if they are exceeding it.

Voluntary - the vehicles speed is controlled not to exceed speed limits, but may be overridden if the driver chooses to do so.

Mandatory - the vehicles speed is controlled not to exceed speed limits, and can NOT be overridden.

In addition to the above ISA can provide different information about the speed limits: -

Fixed - the driver is informed of the current speed limit.

Variable - as above but the driver is also informed about areas where permanent lower speed limits are in operation, like pedestrian crossings or approaching hazards like sharp bends.

Dynamic - as above but the driver is also informed of additional speed reductions due to things like icy roads, fog or major incidents.

Speeding is thought to be a contributory factor in around 29% of road accidents in the UK which result in fatalities.

Trials in different countries around Europe have shown that although drivers still have a tendency to speed if they are allowed, their speed is still reduced. Some studies carried out in the UK claim that just a 1mph reduction in peoples average speeds could lead to a 5% reduction in road accidents on all roads.

A three year study carried out by Leeds University and MIRA Ltd claims that if the Mandatory ISA system were introduced that there would be a 59% reduction in road accident fatalities.