Don't always believe it when your GPS doesn't make sense...or even sometimes when it does. HERE is the story of an American couple who followed their GPS on a route for Tenby Island, off the coast of Wales and actually not reachable except by boat.
Following the instructions, they drove onto a beach and sank in the sand; it took rescuers three hours to dig them out and also to explain, sadly, that there's no ferry in wintertime.
I know the feeling, though: I've had GPS systems that lost a satellite and asked us to drive the wrong way down a one-way street, or to cross a rail line that was 30 feet above us on an embankment. In my family, we call that voice "Sybil," after the ancient prophetess who always spoke the truth, but whose truth could often not be understood by mortals...until it was too late.