Error converting tracks to trips in XT

[chipbl]

Hi all, @jfheath

I'm getting strange behavior when I convert a track to a trip on the XT. I have tried it via BaseCamp as well as via Explore. Here's what happens, and it's not 100% of the time.

1. Import track into XT (via USB from BC, or a synced collection from Explore)
2. Convert to trip using the XT

When I go for a ride or review the turns on the XT, I'll get accurate TbT directions, then I'll get a long stretch of no TbT. Something like, "turn xx in 165 miles." I can still follow the route on the screen, and when I get 165 miles down the road, the TbT kicks in again. There are no stretches this long on our routes.

Maps are 2025.1 on both BC and XT. The track in BC looks fine. Anyone else experience this? Is there any additional information I could provide that might help? Calling out the guru, JFHeath

Thanks,

Chip

[jfheath]

TbT = Turn by Turn ?

I'm unclear - "Something like turn xx in 165 miles". Then nothing, but when you get 165 miles down the road it talks again.
But I don't understand the comment - "there are no stretches this long on our route".

Do you mean that there were plenty of other places where it should have given directions before the 165 mile turn ?

I'm afraid I'm not so much a guru on tracks converted to a trip. I tried them a few times, saw how they could be useful, noted that they too could produce RUT behaviour - that was when I wondered if the recalc was actually using the Track to Trip algorithms rather than the point to point algortihms. But I haven't used them much since.

To be honest - I found the loading a track and selecting Go! more relaxing. Track on screen, no instructions and if you wander away from the route no drama = the track stays put and you get a dotted magenta straight line indicating the general direction you need to go to get back to it. Plus a straight line distance. Much more like the paper map and silva compass and a highlight yellow line drawn on the map that I used for many years when walking cycling, car trips and motorcycle trips.

Let me ponder on that.

[chipbl]

Hi, and thanks for your quick reply!

First off, a big thanks is in order for your seminal work on the Definitive XT User Guide. A truly selfless labor that is immensely helpful. I've read it all, and re-affirmed a lot of what I knew plus learned some new stuff! So thanks for that.

Tbt = Yep, Turn by turn. My turn (no pun intended) - RUT?

I think I've identified the culprit. (Note: your comment about loading a track and selecting GO is a point very Zen and well taken, but I'd like to get more out of what the XT is capable of.)

What I meant by "no stretches this long...." was that the XT showed "continue on XX Road for 165 miles", and there are no trip segments on that road for anywhere near that distance, verified in BC and Google. The TbT works fine until XX Road, then silence, then kicks back in when it thinks I've finished with XX Road.

So a little zooming and digging into the source track revealed ONE via that appears to have triggered a massive, invalid re-route during the trip calculation that must have wanted me to traverse XX Road a million times. That road is actually all of about 350 feet. It's also right near the end of our ride, so I just cleaved off the offending via and all works fine now as a trip on the XT. Oddly, sometimes the errant road is correct, and I can just follow it visually, and sometimes it's completely wrong. But hopefully my solution makes that a moot point.

That was easy because the error showed up at the end of the trip; had it been in the middle, as I've seen before, it might require a bit more surgery on the source track to fix. But at least now I think I know what's causing it - the via closest to the start of the errant road is incorrectly positioned. Just no fun when you create the trip on the go and get that craziness. I'll always verify trip integrity on the XT at home before setting off from now on.

Thanks again, and any ponderings are welcome.

Chip

[jfheath]

Hi, and thanks for your quick reply!

First off, a big thanks is in order for your seminal work on the Definitive XT User Guide. A truly selfless labor that is immensely helpful. I've read it all, and re-affirmed a lot of what I knew plus learned some new stuff! So thanks for that.

Tbt = Yep, Turn by turn. My turn (no pun intended) - RUT?

Thanks for the kind comment. Hardly selfless though - it is one of the way that I learn things. And in any case as the years pass by, I am expecting that others (like your good self) will be able to teach me a thing or to when it slowly starts fading from my memory !!

RUT ? Don't worry about it. When you read about it and want to know more - there are sections in the guide to which you refer - in section 12 - Behaviour Issues.

I think I've identified the culprit. (Note: your comment about loading a track and selecting GO is a point very Zen and well taken, but I'd like to get more out of what the XT is capable of.)

Try it. You'll be surprised how pleasant it is. I was.

So a little zooming and digging into the source track revealed ONE via that appears to have triggered a massive, invalid re-route during the trip

[snip]

It's also right near the end of our ride

Where did that additional Via point come from ? Tracks converted to trips do not have via points - only a start and an end.

You also said that part way along the route it stopped giving directions.

Q: Did you have the option to allow U turns turned off ?

I'm clutching at the straws of experiance that I have here. I'm going to say what Im thinking out loud (ie type it). Some of these snippets may illuminate a light bulb over your head, but I'll still be in the dark without being able to reproduce it.

If U turns are turned off on a normal route, the Zumos stop giving directions if you ignore an instruction.

If a route overlays itself - - ie it heads down a road, turns round and heads back along the same road - you cannot tell which part of the route you are on. One clue is to have the distance to end displayed on the right of the screen either in the Trip Data window or in the bottom right white box. But it is only helpful if you are going the wrong way.

Sometimes - and only very occasionally - I have seen a ghost via point in the route. I haven't put it there, it doesn't appear on the map, but tap skip and you can see that this new via point is the one that it is heading for. I have seen it twice. I've got proof of it once, and repeating the same test dong the same things I was unable to make it do it again. But others have commented.

(Please read this as it is. Don't go saying to yourself no, that's wrong. It might be wrong in the detail- but the gist of it fits the clues that you have given me - and the information might trigger a better solution.

When you select convert track to a trip, it will ask which way to convert it - start to end, end to start. (You think you know where the start is because that is the way you want to ride it - but it comes from the route - so did you check that the track is actually heading in the direction that you want. How did you check ?) If you are in the south and thre route starts in the north (ie you are at the end, not the start) - it is going to put a via point up at the north to mark the beginning and take you to it, then it will start navigating the route that has been drawn from the track heading south. On the way up, there are two magenta lines one on top of the other, but they will deviate from each other 'cos the satnav will have calculated a faster way than the track. You have a good idea which way you want to be going so you follow what you know (think) is the correct road. So you have deviated from the road heading north. Even if the magenta line heading north is directly on top of the line heading south, you are bound to deviate anyway, because the junctions will be all wrong if you are heading in the 'wrong' direction.

It is a theoretical possibility.

When did that Via Point appear ?? Was it shown on the map ?


When you selected Go!, the Zumo asks you to select Next Destination. Did you say Begin or End ?

[chipbl]

Thanks so much for all these ideas. Always great to have them in the back pocket for this and other potential issues.

Where did that additional Via point come from ? Tracks converted to trips do not have via points - only a start and an end.

I am likely using the word via too liberally when compared to Garmin's definition, but what I meant was a breadcrumb in the source track in BC.

All of my routing prefs are off, including u-turns. And I'm pretty sure my route directionals (conversion direction, etc.) are ok.

I'm getting some pretty good trip calculations now; I'll report back if it happens again. I'd like to see it happen in the middle of a route, just to validate my theory of a misleading source track. It's also a great quick-check to use the trip->track overlay just to see what the initial routing computed.

On the begin/closest point/end selection, I played around with all of them. I understand what they do and am getting expected results. The original track came from a friend, and was an exported Kurviger trip. OR, as I thought more about it, I could definitely see a case where if I used a previous track of a ride that I did and I pulled off the side of the road far enough for the XT to drop an errant breadcrumb, that could cause strange results in a future trip calculation! But easy enough to fix.

Should I come across the issue again and am unable to fix it, I'll send over some relevant screen shots to see what you make of it. I'd send the track GPX itself, but likely you don't have US maps installed.

[Scottnet]

I suspect its the same or related to this issue.

https://www.zumouserforums.co.uk/viewtopic.php?t=2985

If so, I reported this to garmin and they confirmed this is a bug but no interest in following up as BC is discontinued.

I have tried many things with no luck.