Tracking was interfering heavily with hand selecting previous/next waypoints. The only way out I can see right now is to make knob press toggle the auto-tracking off completely.

Sounds like a good compromise. Either that or do nothing...

As it stands right now, it only becomes an issue if we go off-track. As long as I'm directly on the route, it seems to work well and select the next waypoint for me automatically. And it's not tough to twiddle the knob to get us back on track. And the new rubber band behavior makes it really easy to see whether or not we've twiddled the knob to the correct waypoint.

At the same time, though, a map error of a few hundred feet seems to be enough for it to skip the waypoint. The illustration I gave above for the missed waypoint was caused by a map discrepancy of only a few hundred feet.

So perhaps it's just a question of tweaking the radius of how far off you have to be from the waypoint. But that opens another can of worms, which is what if you've got a group of waypoints that are very close together. Code the radius too loosely and it might automatically skip ahead two or three waypoints, and not give you the correct turns as you reach them. The Palm software I was trying had this problem.


As far as the directions are concerned. I'm using the angle between the 'current bearing' and the direction of the road after the turn. However at low speeds the measurements we get from the GPS are not reliable.

Well, in my case, I was looking at the arrow and my bearing was correct, and speed had nothing to do with it since I was cruising when I noticed the error in the instruction. Besides, I thought you'd already changed it so that it used the road intersection data rather than the vehicle bearing for its L/R calculator anyway.