THE AA is equipping 1,000 of its 3,600 patrol vehicles with a satellite navigation system to speed up response times to vehicle breakdowns.

The deal is understood to be the largest single fleet order for sat-nav systems.

The national roadside repair and recovery organisation assessed six navigation systems before investing in the Blaupunkt DX-N Professional Satellite Navigation System. Chris Bailey, AA Business Information Systems Manager, said: 'It is crucial for us to save time if we are to maintain our competitive edge; navigation systems offer the obvious solution for us.'

He said the competing navigation systems had been judged according to their ease of entering addresses (some took significantly longer than others), the time required to calculate routes, and the time taken to recalculate a route if a driver diverges from the programmed directions.

The poorest performing system took over 10 minutes to recalculate a route through London when a driver continually made off-programme turns.

Price and the clarity of instructions (both voice and screen directions) were also assessed, leaving the Blaupunkt system the clear winner. The AA is working on a system of sending messages directly from control centres to the in-vehicle navigation systems using geo codes (like map grid references) so that a driver will not have to key in the address.

This saves time and the possible confusion of selecting the appropriate Church Street, for example, where several may exist in the same city.