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

[Scottnet]

I created a scenario that is 100% reproducible to show that the XT does not follow the route when it should do. Sent this to Garmin Support in the UK, they say I need to report this via Reporting Map Errors on Automotive Devices

What a joke, this is not a map error its an software error as I proved in my tests , Bottom line is they don't want to follow up so little or no hope of ever improving the routing on the XT .

Any idea besides for product support that may care ?

[jfheath]

How about sharing the details on here?

If it is a software fault, the same thing will happen in similar circumstances but in a different area. It can be difficult to tease out software issues when the satnav does things differently on different days, at different times, and can be affected by how and where you rode last.

If it is a mapping issue, the details of the road may be wrong - eg speed limit.

And if you have more than one map active (ticked) for the same area, then all bets are off. When I have OSM maps loaded as well as my Europe maps, it will do all sorts of stupid things.

[Scottnet]

Here is the message I sent to Garmin, I have attached the image ( cant figure out how to insert inline) and the GPX file so you can try this, I am using the updated Garmin Map, I do not think its a map error because the when I calculate A to C it works correctly

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I am trying to figure out why in loads of occasions the my Garmin XT routes me through town centres, and routes that seem very odd, and is very annoying.

I have setup some tests, I have 3 way points , A,B and C . All these tests are done with no adventurous routing, and no avoidances and routing option set to the fastest time.

Tests (See image below for visual representation)
1. When I create a route from A to C it creates a route as expected. This route takes 21 mins (Yellow route below)
2. When I add a way point B that is on the route, the route changes to go north through Petersfield and the route takes 28 mins (Magenta Route )
3. When I create the route from B to C it follows the route in test 2.

I have attached all the data you need to test this. Please could you help me figure out why ?


https://photos.app.goo.gl/Bz2ZHy3doxwknHiE7

[jfheath]

Now that is odd.

Sure I will help get to the bottom of this. Not least because I want to know why for myself.

I dont get back to my PC until the weekend, so there will be a delay.

Which maps do you have loaded ? And have you selected the correct map in Basecamp ?

I'll PM my email address - if you can export the route as a gpx file and send me that, it may help me to identify something. If I can !!

[sussamb]

Just tried that and in BaseCamp it doesn't route via Petersfield. If it's doing it on your device that's very strange.

I've also downloaded your gpx file, if I force a recalculate then it follows the route I'd expect and doesn't go via Petersfield

[Scottnet]

Thanks again for your input. This has nothing to do with basecamp. The issue is the routing in the XT. And this is super important because as we know the XT will always recalculate a route.

The Gpx files are attached. All you need is to load those waypoints to your device and then follow the same steps.
I would love to know if the same thing happens.

Please let me know if you need any more information.

Cheers

[jfheath]

Sorry - I missed the gpx file attached to your post. I will scrutinise it when I get home and see what results I get and how to make produce the results that you get.
I'll do this in Basecamp - because those are the screen shots that you provided, but I will also check it on the XT.
But I can't do it til I get to my PC after the weekend.

You said that it has nothing to do with Basecamp ?
Can I ask why you think that - because the screens that you showed were taken from Basecamp.
Or have I missed something ?

You also say that the XT will always recalculate a route. This is not true. It is true that the XT will recalculate a route in circumstances that the the 590, 595 and 660 would not, but for many of my routes, it leaves them alone. Sometimes it depends how your XT is set up.
It definitely depends on how Basecamp is set up to transfer routes. eg - check edit - options - device transfer in BC. If any of those boxes are ticked, it will likely recalculate the route every time. Also if your map on the XT is a different version from the one used in BC, the same.

Dont get fooled by the calculating message when starting a route. It doesn't mean that it is recalculating the route. You will always see the message 'Calculating' for a few seconds. Eg if you have selected a start point 100 miles away, it has to calculate the route from where you are now to get you to the start point that you have chosen - as it ignores any route that you have plotted before that point.

Also, the XT has to look through the gpx file and find any waypoints that you have created in Basecamp with the flag tool, sort out the Via Points and the Shaping points, and produce an image from the thousands of invisible route points that Basecamp creates to ensure that the XT plots the identical route to the one that Basecamp sent. This is regardless of vehicle, avoidances and routing preferences ( although if the Xt spots a difference it will ask if you want to recalculate it).

It does all of this in a few seconds. If you have a long route that is taking around 15 seconds or more to do its calculation, then I reckon that something is wrong with your setup.

But note that if you use routes from other sources - eg Google, MyRouteApp, etc, the Zumos will always calculate the entire route from scratch. This means that you have to be wary of what other people tell you if they are using different software from what you use. All of the Zumos are quite capable of completely ignoring any routing points if the software hasn't defined them in the proper format for a Garmin device.

Routes from Google maps were a case in point a few years ago ( i don't know if this still applies). The Zumo would accept the roads to be travelled, but none of the route points that pinned the route to use particular roads. So if it ever had to recalculate, there was nothing to hold any of it in place, and the Zumo came up with a completely different route to the finish.

So where does the fault lie in that case ? With the Zumo? With the mapping? With Google? With the user? I would say none of these. It is just the way it behaves in those situations, and if the user plans their routes like that, then they will get to know the behaviour and the limitations. What they do to make it work for them would be different from the things that (say) you would need to do.

The above info is based on stuff that I know for a fact from hours of testing. If you are coming from a 660, you will have to forget about a lot of stuff that you know. The XT is a very different beast. The 590 drove me mad when i first changed from my 660 until I realised that I had to re-learn stuff that I thought I knew. The XT has proved to be another very different beast, based more in the 595, but still different.

Sorry, i have prattled on a lot. I'll take a good look when I can get to my PC and Basecamp and the connections I need to load your route.

[Scottnet]

Thanks for the detailed reply. It's good to find someone who knows what they are talking about.

I only connected the XT to BC solely so I could use screen shots from the PC. Nothing calculated on BC.

I understand about calculation to start of the route, even if you are at the start doh, but I have no idea how to get a route from BC to XT without calculating ? But that's a different subject.

Let me know what you find out.

Cheers

[colirv]

I have no idea how to get a route from BC to XT without calculating ? But that's a different subject.

As a start, do as jfheath said above -" check edit - options - device transfer in BC" and untick everything.

[jfheath]

Ok - back home now and have access to Basecamp.

Scott has 3 routes A to C, B to C and A to C Via B.

Only the A to C takes the shortest, fastest route. The other two, both of which involve Point B, take a large loop to the North.

Use Basecamp to Zoom in on Point B to reveal the issue.

Scottnet Route Problem.jpg (15.73 KiB) Viewed 1876 times

Point B is not located on a road. Move point B onto the road and the problem goes away. So does recalculating the route.

So how can it happen that Basecamp will calculate the route in one way and then calculate a different way without anything having changed. The only time I have ever come across anything like this is on Alpine Passes when I was spending winter preparing the route and then came back to it before leaving. Basecamp would not route me over the pass in winter. Seasonal Road Closures.

But that cannot be the case here. Here is a possible explantion - only a possibility, I cannot know for certain.

Route between two points is created.

Scott Rt 1.jpg (131.94 KiB) Viewed 1865 times

An additional point is dropped in error, or the wrong tool has been selected.

Scott Rt 2.jpg (101.16 KiB) Viewed 1865 times

Whatever, an additional unwanted shaping point is now controlling the route

Scott Rt 3.jpg (86.62 KiB) Viewed 1865 times

The offending shaping point is deleted - except this is not the way to do it. This removes the saping point, but leaves the route intact.

Scott Rt 4.jpg (23.79 KiB) Viewed 1865 times

See- No shaping point. But the route remains as it was.

Scott Rt 5.jpg (91.93 KiB) Viewed 1865 times

Which is exactly like the route that was provided. As soon as the route is recalculated it returns to the expected route.


But there were two routes that had this problem, so either the same mistake was made twice - once for each route , or a third route was created from the one that already had the problem.


The correct way of deleting a point is to remove it from the route list. Selecting Remove Shaping Points removes shaping points but leaves the route where it is. The method above is not a programming error - it is deliberately designed by Garmin to get rid of unwanted shaping points without affecting the route. The route is still transferred correctly to the Zumo, and the Zumo will follow it. Until it recalculates !

It is very useful for finding out which sections of a route are recalculated in different situations when riding. I use it for testing purposes.