The speed’s the limit

The UK’s first large-scale government-funded trials of a computer-controlled car speed limitation system are to take place in Leeds this spring.

The UK’s first large-scale government-funded trials of a computer-controlled car speed limitation system are to take place in Leeds this spring.

As part of Department for Transport research into controlling vehicle speed externally, 20 volunteers are to be issued with petrol engine Skoda Fabias fitted with Intelligent Speed Adaptation computers that limit acceleration. Previous research suggests that by making cars obey local speed limits the system could cut road fatalities by up to 58 per cent.

One of the project’s aims is to investigate the system’s cost and benefits as well as the feasibility of an architecture for mass use.

From late March or early April researchers from Leeds University’s Institute for Transport Studies and automotive research group MIRA will monitor the drivers’ behaviour for a month before switching on the system, which will then run for four months. After the system is switched off their driving will be observed for a further month to see if the scheme has made any difference to their speeding habits.

A GPS unit determines each car’s location, and this is compared to a digital map held in an onboard computer to pinpoint the road it is travelling on and its direction. Map manufacturer NAVTECH Professional Services has also included an extra layer of data detailing local speed limits within the city and on all local trunk roads.

The computer compares the driver’s demand for extra acceleration with these and chooses to ignore or respond by controlling the car’s electronic throttle. ‘If a driver is asking for more power and this would put him above the speed limit the car will deny the request,’ said project leader Dr Oliver Carsten, of Leeds University.

There will be no indication that the Skodas are unusual, other than a sticker on the car telling other drivers that the vehicle will be observing the speed limit.When approaching an area with a lower speed limit, the car will alert the driver 300m ahead through a countdown screen integrated into the dashboard. At 100m the car will begin to slow automatically by reducing power and gently applying the brakes, unless the driver has manually slowed down. However, for safety reasons the system can be overridden if the driver kicks down hard on the accelerator or presses a button installed on the steering wheel.

‘Looking at accident statistics, there are few that are avoidable by acceleration. Most involve braking,’ said Carsten. ‘Leeds is particularly demanding as many roads are close together, so the system will be fully tested.’

He believes that with the co-operation of manufacturers the system would be relatively easy to install in all new vehicles, though any digital map would have to be standardised, provided and updated by the government to avoid legal problems if speeding was observed.

Large-scale trials of a similar system have already taken place in Sweden, and while drivers said their journeys were not slowed they enjoyed driving less and felt somewhat controlled.

In future the computer could be programmed to limit speeds in response to bad weather or high traffic density, while the development team is also working on a version for motorcycles and lorries.

The results of the scheme will be available towards the end of 2005, following further tests on fleet and private vehicles in Leeds and rural parts of the Midlands.

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