Gpx file query

For help and advice on the Garmin Zumo XT2.
Steveambrose
Posts: 1
Joined: 06 Jun 2024 11:03
Ireland

Gpx file query

Post by Steveambrose »

Hello I have my friend who shared his GPX files . They were downloaded from ride website and works OK on his tom tom.
When I loaded them via tread all ok except when I come to select it to navigate it's says
"Vehicle profile used to create this route cannot be used with this device recalculate.
I thought the point of Gpx files was to share seamlessly. Any help please. Have I missed something? I don't want us to have different routes.
Thanks
smfollen
Posts: 15
Joined: 10 Jan 2024 20:31
Location: Boston Area
Has liked: 9 times
Been liked: 9 times
United States of America

Re: Gpx file query

Post by smfollen »

I thought the point of Gpx files was to share seamlessly.
In theory, yes. Unfortunately, its not that simple in reality. The GPX format is a public XML Schema, but it is extensible, meaning various vendors (or anyone) can define their own extensions. Those extensions are not supported by all vendors and devices.
Further, the meaning of various terms varies among vendors.

In your particular case here, the vehicle profile named by the tom tom is apparently not recognized by the zumo XT. Look for something like <trp:TransportationMode>Motorcycling</trp:TransportationMode> in the gpx file.

More importantly, different vendors, devices and software applications use different routing algorithms, so may calculate different routes from the same set of user specified route points (waypoints / via points / shaping points). The more points specified when defining the route, the more likely the resulting routes will match, but there are tradeoffs.

You can find lots of information on this forum including "Everything That You Need To Know" viewtopic.php?t=1464&start=70

If you want more details on gpx files and terminology differences, see the playlist here
User avatar
Peobody
Subscriber
Posts: 1451
Joined: 20 Apr 2021 13:33
Location: North Carolina USA
Has liked: 108 times
Been liked: 321 times
United States of America

Re: Gpx file query

Post by Peobody »

@smfollen is correct about the same .gpx file producing different routes on different device. My experience with this is very simple. I have an XT, one of my riding buddies has a Nav VI. We both use Basecamp to create routes that we then share. Most of the time, the devices will accept the routes cleanly which results in both devices creating a route that follows the Basecamp ghost points. However, should either, or both devices calculate the route, those ghost points are discarded and the devices creates a new route between the shaping and via points. At this point I probably don't have to tell you that the resulting routes are often different between the two devices. We both know this, so we try to include enough strategically placed route points to insure that a calculation by either device provides the route that we want. Unfortunately, neither of us have been able to outwit the device 100% of the time. We both know the 'show track on map" trick but that is another discussion and is not relevant to the question of why a .gpx file does not produce the same route on every device.
2008 Honda GL1800 Goldwing
1995 Kawasaki ZG1000 Concours
zūmo XT linked to Cardo Packtalk Bold and iPhone SE.
danham
Posts: 300
Joined: 13 Jul 2018 14:25
Location: Cape Cod, MA
Has liked: 95 times
Been liked: 91 times
United States of America

Re: Gpx file query

Post by danham »

All good information. I'd just add one more variable that people sometimes forget about: maps. If a GPX file is created on map Brand A, then used on a GPS displaying map Brand B, there is a lot of potential for differences in the way the maps are laid out to cause major route errors. Even if the code in the GPX files is 100% compatible, map errors can ruin the ride.

To improve the usability of your friend's GPX files, import them to Basecamp and check all the turns carefully. Edit as needed and then send to your XT.

-dan
Zumo XT, 660, nuvi 760 and many retired units dating back to the GPS III+
2018 Kawasaki Ninja H2 SX SE