Does your GPS take you on goofy detours for no reason?

Question

You are driving home from work and your GPS suddenly guides you down a side street, where you get caught in a ridiculously busy intersection at Noname Street and Anywhere Place, and then guides you right back the way you were going. What causes this? Give details.

Answer 1

GPS navigation systems calculate their route guidance using a combination of mathematical equations, and rules-based programs. The developers of the software are not able to take into account all of the local traffic and road conditions. Strange routing will occur from time to time.

Personally I only rely on my GPS Nav system when I have absolutely zero clue where I am going. So little side detours are of little consequence to me, as long as I arrive at my final destination. I do not use nav for well established routes, such as from going between home and work.

Answer 2

It is probably caused by movement of the satellites that your device relies on for guidance signals.  All GPS devices are prone to do this sometimes.

Answer 3

It happened on the way to a friend's house about 60 miles away. My GPS seems to like detours down no-name side roads when it is dark out. I would assume it's just because it tries to take the "shortest" route (even though it takes you an hour out of the way), not the best route.