Speed-limiting device promises car emission savings

In a move that is bound to please environmentalists and safety campaigners just as much as it infuriates petrol heads, Transport for London (TfL) has announced a six-month trial of a new technology that automatically stops drivers breaking speed limits.

The Intelligent Speed Adaptation (ISA) system is to be fitted in a London bus and taxi, as well as 20 vehicles driven by TfL staff, from this summer. If it proves successful it is to be rolled out more widely, with Southwark Council having already expressed an interest in fitting the device in more than 300 vehicles.

The system works using satellite navigation technology to track the speed limits on different roads. Depending on the mode selected by the driver, it either automatically stops acceleration once the speed limit is reached or advises the driver when the limit has been breached using an icon on the dashboard.

TfL said the technology, which will be available for private motorists to buy from next year, should result in lower accident rates, less congestion and reduced vehicle emissions, while also helping drivers to avoid speeding fines.

"We know the technology works, and now we want to know how drivers in all types of vehicles respond to it," said Chris Lines, head of TfL's London road safety unit. "ISA is intended as a road safety device, but if Londoners embrace this technology we may well see additional benefits, including reduced congestion as a result of collisions and reduced vehicle emissions as drivers adopt a smoother driving style."

Early studies undertaken by TfL suggest the technology will help deliver small savings in carbon dioxide emissions and fuel consumption on both 30 and 40mph roads, primarily as a result of reduced acceleration. However, fitting the device on even a small number of vehicles could deliver wider emissions savings by forcing those cars stuck behind them to drive in accordance with the speed limit.

Moreover, with 25 per cent of congestion on London roads caused by accidents, further emissions reductions could also be delivered as a result of any reduction in the rate of accidents.

The technology is bound to result in opposition from some motorists, but the AA welcomed the trial, arguing that it would help drivers accurately assess whether the technology works.

"Drivers are divided in their views of intelligent speed adaptation - some hate it, some want it," said Andrew Howard, head of road safety at the motoring group. "Many have questions that will be answered only by trials such as those being carried out by TfL."

The TfL trial is just one in a series of pilot schemes being undertaken by road transport companies and councils seeking to cut emissions and fuel bills from their fleets.

Last year, London bus operator Metroline announced that it was to trial a similar device that measures a vehicle's g-force and warns motorists when they are not driving smoothly enough, while Nissan is working on a new " ECO pedal" device that promises to "push back" whenever a driver tries to accelerate too sharply.