Satnav sends driver into river

This story from The Register of a driver who plunged her Mercedes worth knocking on a hundred grand into a river caught my eye. The driver ignored signs warning the track was unsuitable for motor vehicles and drove straight into something of a raging torrent. Why would someone do something apparently so daft?

There is an experiment in psychology where you take an almost empty train and then approach someone and ask if they mind moving because you want to sit there. Most people will protest. Repeat the experiment wearing a peaked cap and the results are quite different - most people will move. It's about the subconscious recognition of a sign of authority.

Maybe people subsconciously view their satnav as some sort of authority figure and will trust it to the ends of the earth. Or maybe they're so comfortable cocooned in their cars that they lose their natural suspicion and ability to reason. After all it seems so all-knowing? 

And is this partly why people are taken in by some phishing sites? If something is done slickly enough and seems official - and of course it's there on your own computer where  presumably you feel comfortable - do people just trust it because their normal judgement is impaired?

Or are some people just daft? Spending that much on a car seems daft to me - but hey -  people do seemingly daft things that turn out to be genius - like driving a 1988 Trabant 4,200 miles from Sheffield to Banjul. And they didn't seem to need satnav....