Occasionally I talk to people, serious-automotive-driver-type people, who trust in their own road knowledge over the insights of GoogleMaps or some comparable internet-driven GPS system.  Y’know…“Maybe it’ll tell you to take Route X, but believe me, Route X is terrible and you should always take Route Y.  I have experience enough to know.”

There has to be something about this attitude that I’m not getting.

Even if you know the roads very very well, your knowledge of them is probabilistic.  “Route X will have awful traffic 50% of the time, while Route Y will have awful traffic only 10% of the time,” or something.  But even very strong probabilistic knowledge will sometimes guide you wrong.  90% confidence means you’ll be mistaken 10% of the time.   And lo! even very confident, experienced drivers sometimes get stuck in horrible traffic.  I don’t think any of them would deny any of this. 

Google actually knows what is going on, on the roads, right at this moment.  If it sends you down a “bad” route, it’s not doing it because it doesn’t know the good route exists, it’s doing it because it has non-probabilistic reason to believe that betting on the good route isn’t going to pay off this particular time.  And lo! the vast majority of the time, GoogleMaps gets you where you’re going at close to the exact time that it says it will. 

So what’s the justification for the mistrust?  Is it straight-up bravado?  Luddism?  Eh?