Interesting little problem. Thanks for including the GPX file.
Ok - so I get to use my USA maps for the first time in earnest.
My XT2 displayed exacly the same results as yours. I thought at first it was because the end point was plotted off route - but that isn't something that I had seen before. I changed the next to last point to a Via - and that got rid of it. But then when I imported it again the probelme reappeared.
So I looked closer at each route point in turn in Basecamp. All was OK.
So I looked at the list in the XT 2.
Look what I found:
- Look-Out.png (143.97 KiB) Viewed 1239 times
Compared to the Basecamp list :
- LookOut 2.jpg (24.74 KiB) Viewed 1239 times
Shandaken Twn is the name that XT2 has allocated to Catskill Park8112. The coordinates are the same. But it has put it into the route twice.
You wouldn't notice this just by looking - the route list shows a number of locations names twice - but they are roads and the points are in different positions.
I tried deleting one of them - but that didn't work on the XT2.
So I created a track of the route and used it as a reference to see what happens if I deleted the Catskill Park shaping point completely. It stayed the same. And when I sent that to the Zumo XT2 - it looked perfect.
Don't ask. I haven't got a clue. I don't know if that straight line is a branch or if it is the same route coming back. I've yet to try to simulate the route from Brios Pizza and Gas to see what it looks like to navigate - and which route it takes.
Anyway - see if you get the same results by deleting that shaping point.
I'll continue to ponder on it - there has to be something about that point.....
... or the number of points
... or the loop back on itself (it is the first point after the loop).
I didn't try to make it a Via . Perhaps it needs on to separate the segments - although Brios Pizza and Gas is a Via point. That should be enough.
I don't know. I've just looked through that section of the GPX file - there's nothing wrong that I can see.
[afterthought] I have just forced the XT2 to recalculate the route. (I did this by going into Navigation and setting avoid ferries), then reloading the route. IT informs that avoidances have changed, so I want to recaculate. Yes please. The double entry for Shandaken Twn is still there, but the route plots properly.
It reminds me of that error in Basecamp when you move a different point to the start or the end. The straight line map that is displayed develops an extra limb - with three straight lines coming out of one of the points !
Edit - just running a simulation from the Brios. The first shaping point on the map is quite close to Shandaken town. THe second point where the route splits is some way from Shandaken town.