Speed limiting technology is being tested on taxis, buses and council vehicles in London this summer.
The technology — known as Intelligent Speed Adaptation (ISA) — is being tested by Transport for London in a trial on all roads inside the M25.
According to the Times newspaper, drivers of vehicles with ISA will be able to select an option that prevents them from accelerating over the limit. The vehicle will also automatically slow down if the driver fails to reduce his speed when he passes a sign marking a lower limit.
The device uses satellite tracking and a digital road map to detect the local speed limit.
In addition to the automatic mode, the device has an advisory setting in which the driver is simply informed of the limit and told whether he is complying. A smiley face symbol appears on the unit if the driver is obeying the limit and frowns if he or she goes too fast.
The technology is likely to be offered for sale next year to private motorists. It's anticipated that drivers with six or nine penalty points might choose to have it installed.
Transport for London (TfL) estimates that, if two thirds of London drivers used the devices, the number of road casualties in the capital could be reduced by 10 per cent.
The improvement in road safety could reduce congestion, a quarter of which is caused by collisions. Vehicles obeying the limit would also consume less fuel and be less polluting.
TfL’s trial will include a London bus, a licensed taxi and 20 cars driven by road engineers, traffic managers and highway inspectors.