Deviation from route

[colirv]

I transferred a route and track to the XT. It transferred instantly, so no recalculation - to be expected, as the maps are identical and every transfer box is unticked. However, when I followed the route it deviated in a couple of places, getting back on track further along. On each occasion I decided to follow the route, rather than the track (which I also had showing on the screen). Once home, I downloaded the route back from the XT, and the track log, both of which are shown in the image below. The route is unchanged from what I originally transferred to the XT, but the route it told me to follow was as per the track in the image - i.e. different.

The settings in Basecamp and on the XT are as close as they can be, in particular both set to Fastest Route with similar avoidances, and to motorcycle (XT usage).

Has anyone any suggestions as to what might be happening? The XT is less than a year old, and so far has behaved perfectly.

[FrankB]

No answer, just something you could try.

Try the different options when starting the route:

Start
Closest entry point
End

[Peobody]

@colirv, you have posted about something that has frustrated me since my first days with the XT. I learned quickly that I needed to transfer the route and the track to the XT, show the track on the map, start the route, and then look for deviations before ever riding the route. More often then not I will find deviations. I often have the sense that a calculation is going on during transfer though. That is something you did not experience though. I would be curious what you see if you transferred the route and track again and then compared them without riding. This would identify whether the deviations occurred during transfer or during the loading of the route for the ride.

[smfollen]

I like to always recalculate the route on the zumo immediately after transferring it from Basecamp. That allows me to see any deviations while siting at my desk, avoiding surprises on the road.

Even when using the same map on both Basecamp and zumo, and with all route preference and avoidance settings as similar as possible on each of the two, there can still be some differences in route calculation.

Trip Manager (viewtopic.php?p=24080#p24080) includes a very nice feature to compare routes calculated by the zumo with those defined in gpx files.

Adding a shaping point to the route where differences occur will typically resolve the differences. Trip Manager supports that too.

[FrankB]

Oh yes.. something else that often triggers deviation is : Traffic info.

[colirv]

I would be curious what you see if you transferred the route and track again and then compared them without riding. This would identify whether the deviations occurred during transfer or during the loading of the route for the ride.

The route in the image is the route transferred back from the XT. It hasn't changed. The XT loads the route, then gives instructions (verbally and pictorially) that differ from it.