GPS devices are a great tool, but they are not fool proof.
It only took me a few hours of using one to learn I could not depend on it for 100% accuracy.
I try to know about where I am going before I start a trip. If there is a conflict between where I think I should go and where the GPS directs me to go, I follow my instincts.
“A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.”
― Douglas Adams, Mostly Harmless