I can't say I've ever really had one of those but I find that Google frequently has what I like to refer to as "Oh, Google is in the mood for a country drive" moment. It will take you on a bunch of back roads rather than a major route, presumably to save 2 minutes (assuming you don't miss a turn). Which is particularly annoying in winter (like this morning!) when there may be snow and ice on said back roads.
The worst I've had, which wasn't really that bad, was when I was taking a friend to pick up a canoe in rural NH and they were on a snow covered gravel road. Google routed me on a long drive on said road. Which was OK but still slow going. When we got there, they guy sort of laughed at the direction we had gone and said we should have come in the other way which only involved a mile or two of said road.
The worst I've had, which wasn't really that bad, was when I was taking a friend to pick up a canoe in rural NH and they were on a snow covered gravel road. Google routed me on a long drive on said road. Which was OK but still slow going. When we got there, they guy sort of laughed at the direction we had gone and said we should have come in the other way which only involved a mile or two of said road.