Satellite navigation systems "seriously undermine road safety", Dutch academics claimed today.

The Stichting Onderzoek Navigatiesystemen (Navigation Systems Research Foundation) warned that software errors in sat-nav devices are preventing motorists from finding ring roads around cities.

Almost none of the navigation systems tested by the organisation was found to take adequate account of hierarchies in road networks.

As a result, motorists are unnecessarily being turned into "kid killers" by being sent through designated low-traffic residential areas and roads which are not designed for through-traffic.

The Foundation predicts "catastrophic developments" if authorities do not intervene, including more traffic accidents and casualties, and side roads becoming jammed with volumes of traffic for which they were not designed.

"TomTom blames the problem on the information supplied by the authorities, but that cannot be true as Nav4All [a free navigation system for mobile phones] does in fact send motorists to their destinations via the appropriate roads," said J P van der Ende, chairman of the Stichting Onderzoek Navigatiesystemen.

A direct consequence of these software errors is that the automatic traffic jam avoidance features of TomTom and other navigation systems cause local roads to become jammed with volumes of traffic for which they are not suitable.

This increases the number of traffic accidents and casualties, and disturbs the peace and the environment of residential areas, according to the Foundation.

"The authorities have a responsibility to take action in good time. Systems which unnecessarily endanger road safety and the flow of traffic must be banned, " said van der Ende.

"At the moment the problem is still relatively small, but in a few years' time, when everyone is using navigation systems, the consequences will be incalculable."