Mar/April 2009

Trials of a system that limits vehicle speeds automatically to the roads they are on have been launched by Transport for London. Factors monitored during the trial will include driver behaviour, journey times and the impact on vehicle emissions.

Under the six-month trial, drivers will be able to set their vehicle up so that acceleration is blocked as soon as the current speed limit is reached. For safety's sake, the system can be overridden by a single touch of a button.

The scheme requires each vehicle to be able to monitor its current position by GPS (much as is done with standard satnav devices), and will require the fitting of a discrete limiting device in the vehicle. This in turn depends on the availability of a new speed limit map dataset released by TfL itself earlier this year.

This data, which is known as ISA mapping (for Intelligent Speed Adaptation), incorporates legal maxim speed limits for all roads within the area encompassed by the M25. Interestingly, the mapping has evidently been created by recording the actual locations of speed limit signs on roads, and inferring the limits established between them. It is available to satnav and other developers to use as required in their applications.

 

Twenty vehicles are being equipped specifically for the TfL trial, though other users are being encouraged to experiment with the ISA data as well. The specific vehicles include a taxi, a bus and various cars operated on behalf of TfL. One London council, Southwark, is reportedly interested in fitting up to 300 of its vehicles with the system.

Motoring organisations such as the AA have given a cautious welcome to the initiative, though media commentators have suggested it is unlikely that such a system would attain the force of law in the foreseeable future.

Speed limiters are of course already fitted as standard on many commercial vehicles and cars, though their top speed usually has to be pre-set, or adjusted manually according to the speed limit or traffic conditions. It does not automatically change according to the road the vehicle is on.

However, against this background a new development by telematics specialist Masternaut is particularly topical. The company has launched what it calls a Speed Tracker tool. Its primary use is to deliver alerts in the office in real time when any driver exceeds the speed limit for the road currently being travelled; but Masternaut points out that it also has the potential to be able to offer fully-automatic speed limiting of vehicles whenever they enter speed-restricted areas.