It was me that identified and named the RUT issue - and having identified it I was able to make it happen on any route. That was important - because I need it to be predicatable. If I wasn't certain that it would do it every time, I couldn't know whether I had fixed it or not. One early success was coming across it when previous rides along the same route had behaved Ok. I sat at the side of the road, sidestand down, drinling a coffee from a flask, trying to recall the last two hours. What had I done that was different ? Later another success was when I discovered that on the same route, it didn't happen. But on that day I had I stopped at the side of the road to get screen shots and managed to delete the active route. So I rebuilt it using the saved waypoints. So I had things - something that seemed to trigger the behaviour. Something that prevented it from happening even when the same trigger was employed. And that after lots of testing, lead to the solution.
It happens with any imported route - ie one that has been put on the XT1 2 or 3 as a GPX file. The XT imports the data from the XT file, changes the names of points and treats it as though an idiot has prepared the route - with route point being badly located in nearby fields etc. If you go off route and the entire route is recalcluated - the zumo decides that it cannot trust the route - so it treats it as if it hasn't got any route points. Instead of heading for the next route point plotting a new route on different roads, it finds the place on the plotted route that is closest to your current position and heads for that. If you have just had to make a detour by heading off at right angles, that closest point is behind you. Ignore the u turn request it plots a new route to get you to go back - not to where you left the route, but to the palce where it last asked you to turn back. And it can never escape from that model. In my tests, it was still asking me to go back and follow its ariadne's thread of turn back points to where I left the original route and then pick up the way thata it intended to go in the first place. I was only a mile from meeting my original route. It was taking me 12 miles bakc and then anoher 18 miles to reach the point whic was only a mile ahead of me.
But there are a couple of solutions - both of which fool the XTs into thinking that the route has NOT been imported as a GPX file, and that it has been created on the zumo screen:
On the XT1,
Load the route, select Go ! and immediately go back to the main screen and select the Trip Planner APp, and choose 'Saved Trips'. That gives alist of trips (routes) available on the XT - Saved Trips (those created on the XT) and Imported Trips (those imported as GPX files). But also at the top is 'My Active Route'. Select that and click the 'Save' button. Give it a new name - I use the old name with an @ or asterisk * in front.
Then go back to the trip planner and your new route will be listed under 'Saved Trips'. Load it in. Note that it has a new first route point - that is where you are now. Say Go ! Select the next destination. Ignore the one labelled coordinates - your position when you performed this little trick. Ignore closes entry point. Choose the thrid point - the start point of the original route. Run that.
That route cannot be forced into displaying RUT behaviour. It behaves perfectly.
One the XT2, T
There is an easier method to get the same result. Apps -> Routes -> Select a route. (Yes Garmin have at long last stopped using the word 'Trip' and started using the word 'Route'.
No need to say Go ! Just tap the spanner / wrench and select Copy. Give it a name, and load that route. Same result - cannot be forced into a RUT situation.
I don't know whether or not the XT3 has the same copy facility. I guess that it will.
The other solution ..
.. is one that FrankB from ZumoUserForums has develped with a very modest amount of research and testing help from me and a few others. It is a windowss based program which takes a GPX file and places it (using the USB cable) in the .System/Trips folder as a trip file - which is what the garmin uses. So the Zumo never sees the GPS file. When you start up the zumo after using Trip Manager - the route is there in the menus. Providing you don't allw Drive or Tread to synch via your phone, your route remains unaltered. Route points are not moved, they are not renamed, and I have carried out a number of tests on routes on which I know how to provoke RUT behaviour - and they refuse to do it.
Brilliant. It's what I use all of the time now for transferring routes, tracks, waypoints to the Zumos. All free. Frank is a professional programmer who does this sort of stuff for fun. He has made it and the source code freely available.
If you want to know any more about any of this - probably best to start a new thread to avoid hijacking this thread any more. Mention my @name so that I am alerted and I'll point you to various sources of research, information, videos or help.
Now what was I doing before I saw that little snippet from
@ST1100Y ? Ah yes - I was browsing to find the name of this Chinese satnav that
@Uncle Phil is using. I'm curious.
That'll wait 'til tomorrow now !