O'Reilly Radar reports a road sign in a UK village warning drivers not to follow Satnav, and briefly discusses the issues of getting changes made to large databases. Not a new problem.
After several unfortunate incidents, the village of Exton posts a sign which reads: "No wide vehicles. Do not follow satnav. Very narrow road.". Presumably, if the local council have gone to the length of putting up a notice, they've also tried contacting the Satnav data suppliers, but failed to get the data changed.
The UK Ordinance Survey (which is of course completely closed-source) justifies its expensive habits by claiming that it regularly visits sites on the ground to ensure they correspond with maps. But it doesn't seem to encourage feedback from the rest of us.
Open source projects like Open Street Map rely on user contributions, but then you get the Wikipedia set of issues. Are 'the public' always right? Can you always trust us? And of course relying on users makes the whole thing less systematic. (Where I live, for instance, is shown as open country on Open Street Map: they just haven't got round to it yet. Perahps that's my fault, but then I can't contribute to everything.)
Google Earth is an alternative, but then its photographs are not updated very often (think of the cost, not to mention the carbon footprint...) and photographs can be just as misleading as maps sometimes.
As we come to rely on databases more and more these issues will become more serious. If we rely on 'them' to collect the data, we end up speaking to a call centre when we want to correct it: we become just another 'customer' who needs to be managed according to a set of pre-selected options. (Press 1 to pay your bills, press 2 to change your data...) If we do it ourselves, then the results are patchy and not necessarily any more trustworthy.