Originally Posted by Strong Bad
If you come up on a "Y" and the GPS doesn't have both roads (one marked as race course) it is nearly impossible to tell which is the correct until you are way past the "Y" and you see that you have diverged from the correct route. GPS tracking error commonly places you off the track on the screen. I'm NOT a big fan of having to turn around and backtrack hoping that the guy behind you didn't make the same error and you meet him coming the other way.
That is exactly what happened to us in '06, backtracking out of a wrong turn and hit another 8-truck head on. When I got in a few hours later it had knocked out the hydraulics to the steering and power to the Parker pumper and intercom. If only they had been looking at the course notes.....