According to research carried out by DirectLine for the Daily Mirror, satellite navigation systems are being blamed for 300,000 road accidents each year.
(Over 1.5 million drivers said that they had driven badly because they were consulting the devices, either by veering across lanes or making illegal manoeuvres. Might I suggest that if a sat-nav gives you an instruction that is likely to leave you in the middle of a river, or driving the wrong way down a road, ignore it.)