Motoring: Jam-busters march

Navigation systems are suddenly affordable, says James Ruppert

BANK HOLIDAYS mean a wonderful opportunity to visit far-flung relatives or simply pop down to the coast for a well-earned break. Unfortunately everyone else has a pretty similar idea. So how can we avoid jams, not get lost, keep our sanity and avoid spending our Bank Holiday in and around a motorway tailback?

Since this paper's last look at in-car navigation systems, prices have dropped dramatically. Two years ago, they cost more than pounds 3,000, now they are around pounds 1,000 to pounds 1,500.

At just pounds 1,099, Blaupunkt's TravelPilot RNS 149 suddenly puts high-tech route planning within reach. This is the first integrated navigation and in-car entertainment system to fit into that standard hole in the car dashboard known as the DIN - and it does not require a separate navigation CD box in the boot. Installing the device takes an hour.

At the beginning of the journey, drivers simply key in their destination street name and instruct the system to calculate the best way to get there. This can be selected on the basis of the shortest or fastest route, avoiding motorways, traffic tolls or ferries. There is even a traffic-congestion function, which allows the driver to make a detour from the recommended route.

The software re-calculates the vehicle's position to direct drivers around delays rather than immediately back onto the original route. The Blau- punkt uses GPS (global positioning satellite) technology. The pattern of the road network is matched to the electronic maps stored on a navigation CD that is supported by speed measurements and a gyroscope.

VDO's CARiN system also uses GPS, an on-board gyroscope and a feed from the vehicle's speedometer to guide drivers to their destination by spoken instructions supplemented by a visual display. Details of the whole of the UK and all major routes in Europe are contained on a single CD loading into the central unit.

Prices start at pounds 1,349.99 for a SY420 cassette-tuner and a monochrome display, and rise to pounds 1,499.99 for the SY522, which has a stand-alone colour display.

Traffic information is the key, and it is the terrestrial systems which offer more direct help in avoiding congestion. The AA recently launched Personal Roadwatch 1800 (pounds 29.99) in response to the RAC's Traffic Alert 1210 (pounds 19.99). The hardware for the AA system comprises an in-car device which informs the drivers of potential delays on all motorways, trunk roads and A roads up to 15 miles, or three junctions, ahead.

The information in this triangular plastic box is displayed using a series of symbols. It even lights up with a smiling face when you start your journey. Compared to the RAC's blue crucifix, which has annoying flashing LED lights, the AA Roadwatch 1800 is much simpler to understand.

Both systems use sensors mounted at the side of the road which log traffic speed. Unfortunately it is hard to trust the information, and this encourages drivers to risk a hold-up in the expectation that it will probably be clear by the time they get there.

However, both systems are supported by excellent traffic information lines. The AA uses Vodaphone and the RAC Cellnet. Dial a four-digit numberand a pre-recorded voice gives your location and the local road conditions. If you want to speak to a human about alternative routes, it is possible to transfer to a travel in- formation adviser.

CARiN 01869 320333; RAC 0990 533533; AA 0800 0721800; Blau- punkt 01895 838360