Originally Posted by
surak
My 520 would start giving me opposite turn directions at times too, usually after I missed a turn and had to make a u-turn somewhere.
The 520 just provides basic track following navigation.
The Garmins can be confused if you are at a place where the track also returns in the opposite direction. They can pick up the wrong leg especially when you are stopped. The Garmins lose heading when you are stopped. Usually, the sort themselves out but restarting the track in a place with one leg and moving in the right direction should get it to working properly again.
Originally Posted by
surak
Also use RWGPS for routing, so it could be some weird interaction between the two.
No, not really.
Every route planner produces the same sort of file. There no routing information in the files.
The files are just a list of coordinates that trace the turns and curves of the path you want to follow.
The Garmin Edges create a list of turns by walking the track and picking roads on the map installed on the device that the track appears to follow.
Ideally, one would use the same map to plan the route as is installed on the device. But, if it's fairly close, it still will generally still work.
The newer Garmins use Openstreetmap maps. One should try to use that when planning the route.
The Garmins can have issues with roads/paths that are right next to each other. And sometimes, they do shortcuts off the planned track.