Routing errors (again) - any idea of a point of contact that may care ?

[Scottnet]

Thanks for taking the time to dig into this, however I think you have been mislead by BC. This has nothing to do with basecamp.

I moved the waypoint B to exactly on the road and it makes no difference , as I suspected. The reason you see a difference is that you are calculating the route on BC.

To test this load these waypoints to the XT and then create and test all the scenarios on the XT .

[jfheath]

Well, I reckon that I know what it will do. But you presented the problem in Basecamp, and I identified a problem with your gpx file and presented a solution in Basecamp.


Or are you telling me that you were only demonstrating the XT route in Basecamp by i seting a shaping point, and then removing it so that it could not be seen.

I will test it in BC, by generating a route on the XT from just those Waypoints A and C. I am pretty confident that it will work as I expect.

But your set up will be different from mine. It will have built up a riding history. You will have different settings. Short of telling you to do a factory reset, ensuring that your OSM maps are not ticked in mymaps, we are going to get different results.

You seem to be hell bent on blaming the equipment - and to be fair I was the same when I first set hands on a 590 when moving from the 660. But it is a computer. It deals with the info that it is given, and you just have to know how to expect it to behave.

I can help. But you have to be prepared not to throw me curved balls, or put obstacles in the way.

[Scottnet]

I absolutely appreciate your input and interest. I have no intention of throwing any curved balls.

I have no intention to blame the equipment, just trying to verify if what I uncovered is a bug

If you see way back in this thread I explained that this has nothing to do with BC . I only used it capture a screen shot.

Is it possible your could try this on your XT to see if you get the same results.

Thanks again

[jfheath]

Ok - I have taken your original gpx file and transferred it to Basecamp and from there to the Zumo XT.

Since BC created all points as Waypoints, they are no available for me to use to create routes from scratch on the XT, using the trip Planner App - so when adding the start, I just scrooled to favourites and picked up your Point A. Since I am 200 miles further north, this made it a lot easier.

I have screen shots of two of these - the ones that routed you via Petersfield. No problem whatsoever. The Zumo created the route and preview map is available to view. (This feature may need to be turned on in Settings->Driver Assistance->Route Preview).

It is those screen shots that I have reproduced below.



First the route with the start and end points and the Test B Via Point

XT A-B-C.png (66.33 KiB) Viewed 1355 times

A second route made in the same way, going from B to C

XT B to C.png (109.61 KiB) Viewed 1355 times

So that works perfectly well on my device.

-----

Now looking at what happens when I load in the routes from your gpx file.

XT Trip ABC.png (36.43 KiB) Viewed 1355 times

And the map that can be displayed

BC ABC Route.png (70.93 KiB) Viewed 1355 times

Aha - it is wrong, isn't it ?

No - that is perfectly correct. Assuming that the XT hasn't recalculated the entire route when it was transferred then the XT will reproduce exactly the route that was sent to it from BaseCamp. No calculation is required and usually no calculation is even attempted.

Now, you'll have to pay attention here, because no other stanva that I know of will do this. You can use Basecamp to plan a route and mess around with all of the settings - road speeds, avoidances, curvy roads and such like. You can even remove all of the shaping points (just leaving the Via Points in place). The Zumo will receive that route and it will not alter it. It shouldn't even try to calculate it. It just takes whatever has come from Basecamp. It has been this way since Mapsource and the Zumo 550. Most people don't know about this feature, or don't care. Take a look at the text of the gpx file, you will see a load of entries like this.

<gpxx:rpt lat="50.928368987515569" lon="-0.919632995501161" />
<gpxx:rpt lat="50.928754974156618" lon="-0.918838977813721" />

These are two consecutive lines taken from your gpx file. They are gpx extension commands which describe the position of an invisible 'rpt' - route points - they will be just a few meteres apart. For your 3 routes and 3 waypoints, the gpx file contains 1411 lines. Most of them are due to these invisible points. I call them Ghost Points. They are there, you can't see them and most people don't believe that they exist.
But you can see where they are in Basecamp if you take a route and get BC to convert it to a track. It shows the track with hundreds of dots. All BC does is take each ghost point and replace the '<gpxx:rpt' tag with '<trkpt' The dots on the tracks are exactly where the ghost points are in the route.

All of those points stay in place until the XT has to recalculate the route. It may do this if you wander away from the plotted line for example (assuming that you allow automatic recalculation to take place). It may recalculate only the current part of the route to the next routing point. But in some cases, the XT will recalculate every part of the route - eg if Skip is pressed when navigating.

It will also be foreced to recalculate the route from Basecamp if the map in the XT is different from the map in Basecamp, or if the BC setttings in edit->options->device transfer are not unticked -

Ok so what the XT has done is received the route that garmin sent and no calculation of the route has taken place. Ignore the word 'Calculating' when you load it in. It doesn't necessarily mean it is calculating the route. The fact the you got a route that is still heading to Pertersfield is evidence of that.

Ok - that isn't what you wanted. (Even though that is what you sent from Basecamp). How do you force the XT to recalculate the route ?

There are a few methods. Change the vehicle type or the navigation type. Both accessible from this screen.

XT Trip ABC.png (36.43 KiB) Viewed 1355 times

Click on the motorcycle, choose car. The route will recaculate - it has to to use the preferences that it has stored for the car. The route will calculate correctly, and you might be forgiven that this is because you are using the car profile and not the motorcycle. Not so. It is because you changed profile from what it was to something else.

Then click on the car and change it back to a motorcycle. It will recalculate the route again, this time using the motorcycle preferences, which is what you want.

XT Preview ABC.png (35.59 KiB) Viewed 1355 times

The other method is to click on the spanner. In here you have an option to change the route preferences. It is probably set to Faster time. Change it to something else. Straight line or shorter distance. It will recalculate and see the changes on the map. Then change it back to Faster Time.


Another method that forces recalculation is to go to settings and change the avoidances to something different, and then change them back again.
But I find that changing bike to something else then changing it back to bike again is easiest. But I will re-emphasise that it is changing the profile that forces the recaclculation. It isn't becasue you changed the profile to a car.

But it should never be necessary - the route that you get from Basecamp should be perfectly OK in most situations.


Most mapping software for satnavs simply provides the route points for the Zumos. It leaves the Zumo the task of calculating the route for itself every time. MyRouteApp is one exception that I know about. It produces a load of ghost points. I am not sure why they do this, because as soon as the XT receives it, it recognises that the map that was used to create the route is different, so it has to calculate it all again anyway.

[Scottnet]

Thanks for all that, certainly helps confirm my understanding of how this works.

On my device I created a new route using a,b and c . No bc involved at all, device not connected to PC. It creates the route wrong via Petersfield. Yours creates the correct route. I would love to understand why.

My maps are 2022.10 and software is 6.2

Any idea?

[jfheath]

On my device I created a new route using a,b and c . No bc involved at all, device not connected to PC. It creates the route wrong via Petersfield. Yours creates the correct route. I would love to understand why.

My maps are 2022.10 and software is 6.2

Any idea?

Right - we are making progress.

It has to be something different in the settings between mine and yours.

Motorcycle, faster time. I have no avoidances set - except unpaved roads.
Try this. Settings->Navigation->Tolls and Fees. Set it to Allow.

Then load up your B to C route. It will probably tell you the settings have changed. Yes - recalculate it.

Mine will go to Petersfield if I dont allow tolls.
It goes direct if I do allow tolls.

(But that doesn't explain why your A to C route worked OK ! )

Try it anyway - it has to be something like this.

[Scottnet]

So yes if I allow all tolls it routes it correctly!!

So this is bizarre and raises 2 questions

1. there are no tolls anywhere in that area that I know of.
2. Why does A to C work irrespective of the tolls setting.

The fact that A to c works makes me think its not a map issue.

So you can replicate exactly.

How do we report this and get this fixed. As I've said before every thing I send to garmin they don't even bother to try an understand/replicate they just tell me to report a map error.

[jfheath]

How do we report this and get this fixed.

Well I wouldn't report it to them yet at all. We don't know the reason for it doing it - nad it could still be a mapping error.

I have just tried a route from A to C on the XT, and it too re-routes if tolls are set to Avoid. So it is consistent in avoiding a certain section of the direct route between A and C.

That suggests that something along that route is marked as a toll road.

To find that needs a lot of testing - Moving on of the points in to halve the distance. And test.
Depending on the results move A or C In or out by half the distance and see what happens.
Eventually you get to pin point the section of road that is marked as a toll.

And if that turns out to be the answere - then that is a map fault that is reported to another site. A precise statement.
This section of road is incorrectly marked as having a toll. Give the name of the road and give lat an long - or a gpx track identifying the scetcion. No opinions, no argument - just a fact that they can test, duplicate and get it fixed.

If you cant find a culprit, then its back to the point we are at now and come up with another idea.

How big an issue is it ? I always allow toll roads. Mostly, motrocycles don't pay tolls - it takes too long for the rider to take his gloves off, get wallet out, find cash and reverse the process for them to bother.

[Scottnet]

Can you double check A to C with avoid tolls. Mine works correctly and I'm sure previously you said yours did to?

The point is its only when you add B with avoid tolls that it gives the incorrect result.

[jfheath]

Can you double check A to C with avoid tolls. Mine works correctly and I'm sure previously you said yours did to?

The point is its only when you add B with avoid tolls that it gives the incorrect result.

Yes - it certainly changes. Previously I had said that it went direct - but at that point I hadn't fiddled with Toll road settings. Min is always set to allow.

When I did fiddle, it changed route. But I doub;e checked as requested. I got the same two routes, but reveresed from what I remember. This is what I get now. (note the detour south is what I got last night for A to C - when B-C headed to Pertersfield - that isn't new behaviour.

Avoiding Toll Roads:

XT A-C Avoid Tolls.png (68.99 KiB) Viewed 1336 times

Allowing Toll Roads

XT A-C Allow Tolls.png (67.63 KiB) Viewed 1336 times

Now I mayhave made a mistake last night, I don't think so, but it was late, so I may have done.

It is making me wonder if the date issue and historic traffic flow is coming into play. To check that, I'd need to reset my XT, and that would lose my active logs, which - having just had a long tour - I don't want to do until I have downloaded them and transferred to my mapping program.

There is more to this than meets the eye. I'll revisit that previous test tonight - but it night need to be next Sunday night to test properly.