Fri Dec 22, 2006 12:47pm ET

BERLIN, Dec 22 (Reuters Life!) - Motorists who seem to turn off their brain when switching on their car's satellite navigation system have had a number of spectacular crashes in the past year -- but occasionally they're right to blame the machine.

Drivers obeying directions given by a sultry satnav voice have crashed into rivers, construction sites and roadside toilets in Germany, and had similar accidents in Britain.

"It's hard to understand how these things can happen," said Maximilian Maurer, spokesman for the German motoring club ADAC.

"It's not as if people are driving in a tank with only a small slit to see out. You'd think they have their own eyes and brains engaged to make decisions and not rely on the satnav. I used to think satnavs were 'idiot-proof', but perhaps not."

In October a 53-year-old German, obeying his satnav's command "Turn right now!" jerked the wheel over and crashed into a roadside toilet hut 30 metres (yards) before the crossing he was meant to take, causing 2,000 euros ($2,600) damage.

A few weeks earlier, an 80-year-old motorist also followed his satnav instead of common sense and ignored a "closed for construction" sign on a Hamburg motorway. He hit a pile of sand at high speed but was not hurt.

"I just thought the navigation system knew a shortcut," Volker Heinemann was quoted as telling a local newspaper. His car had to be towed away.

In southern England a 29-year-old woman survived unscathed after misreading her satnav and driving the wrong way on a motorway near Portsmouth at nearly 120 km (75 miles) per hour, according to a local newspaper.

When stopped after 22 km of dodging oncoming traffic, she told police she had only followed the satnav orders.

CHELTENHAM OR CHELMSFORD?

In early December, the American band "Viscount Oliver's Legendary Four Tops" missed their own sold-out concert in Cheltenham, southwest England, after following satnav directions to Chelmsford -- 220 km to the east.

"Whoever tapped the place into the satnav got it wrong," the band's tour manager Alan Frazer said.

An ambulance driver with a faulty satnav drove more than 600 km while transferring a patient from one hospital in Ilford east of London to another in Brentwood -- 13 km away. He was near Manchester, northern England, before realizing his error.

Experts say that as cars get smarter, some people seem to get dumber, and the problem increases as more vehicles are equipped with the devices. ADAC said one in three new cars in Germany has satnav, and retailers say they are among the top Christmas gifts in Germany this year.

Joachim Siedler, spokesman for market leader Blaupunkt, said it was absurd to blame the gadgets for human errors and noted motorists are clearly warned the devices are there to help, not to take decisions.

"If a traffic light is red it's obvious you have to stop even if the satnav says 'drive straight on'," he said. "People who drive into rivers and then blame their satnav are just too humiliated to accept blame themselves."

One German did drive his car into the Havel River near Berlin on a foggy Christmas Day. He said his satnav had made a ferry crossing look like a bridge.

ADAC spokesman Maurer said humans are ultimately responsible for the blunders but noted that satnavs are not infallible.

"I was on a motorway recently and my satnav said 'turn left now'," he said. "If I had done, I would have crashed into the guard rail. It was using an outdated, pre-motorway map."