Looking for the best start option to begin a planned route.

[FrankB]

@proofresistant
@smfollen

Before you spend a lot of time, please check all your via/shaping points for something like this.

Cep.jpg (119.46 KiB) Viewed 601 times

This misplaced Shaping point was the cause for a CEP going terribly wrong.

This was the post back then. viewtopic.php?p=5794&hilit=glitch#p5794

Frank

[jfheath]

I'll share with you the observations from my tests with the XT when I first got it.
They might save some time.

There were very early versions of the XT1 software. I'll come back and put in the actual version numbers when I find my notes.

CEP = Closest Entry Point

1. CEP heads for the next via point only. It was nothing more than an automatic version of selecting Go! and choosing the next destination. Only the Via points are listed. I was underwhelmed with admiration for this new feature.

2. An improvement - CEP would head for Via Points or a shaping point IF (and only if) it had been created as a Waypoint using Basecamp's Waypoint flag tool (which means the point appeared in the 'Favourites' or 'Saved' apps. Shaping points that had not been saved as Waypoints did not attract CEP's attention.

3. Any route point was found by CEP. - via or shaping, waypoint or not.

4. The closest location on the route to the bike's current location was located. This is difficult to prove as when it joins the route, it is then going to pass through the next route point anyway. So some cunning route design and placement of via / shaping points is required to prove that it isn't heading for via or shaping points. Its heading for the route where it is closest. I think that it probably finds the closest ghost point since they are spaced very closely together.

Subsequent versions seemed to improve behaviour when the Zumo bike was facing the wrong direction. I didn't notice when that happened.

I haven't tested it with the XT2 - but I doubt that they would have changed by going back to heading for route points (via/shaping). But on the XT2, what we do know is that shaping points are not set in stone. The Tread app and the Garmin XT2 will move them - often onto nearby faster routes - taking the route with them (or it maybe the route that is recaclualted between via points, and it takes the shaping points with it.

And changing any via point to shaping point will cause that to happen again - even without the XT2 being involved - the tread app will do it all by itself.

[Trilergy]

I always add a VIA point somewhere close - usually a KM or 2 away) to my starting point. Sometimes in my area the satelites don't connect quickly enough so if I select from the start, by the time the sats sync it tries to take me back. THey have usually connected by that VIA point so it continues from there. I usually know my way to the 1st via so not worried about the XT2 telling me to go elsewhere.

[proofresistant]

This was the post back then. viewtopic.php?p=5794&hilit=glitch#p5794

What exactly is wrong with this shaping point?
From my point of view, a well-functioning CEP should be able to handle this.

You know there is a pizzeria on the way, you just want to drive past it, but if you are hungry and it is open, you stop there for a break.

The route tracker knows this too, and everything is OK during the check before the trip.

Then you need the CEP function and that's exactly when you get a problem?

Sorry, but this kind of software behavior is not acceptable, and it's certainly not a route planning error on the part of the user.

[FrankB]

What exactly is wrong with this shaping point?

Well. In the 1st place I did not meant it to be there, it should have been place at the main road. Bruchstrasse. My fault I did not pay attention.
2nd When driving you need to turn right, make u-turn, turn right again, just to be on the same road.
3rd When starting the route from my current position with CEP it skipped nearly all shaping points and wanted me to take the Autobahn.
4th If the Shaping point is moved to the Bruchstrasse all is well.
Besides I dont like Pizza!

6 Route different from the original.png (639.86 KiB) Viewed 590 times

Sorry, but this kind of software behavior is not acceptable, and it's certainly not a route planning error on the part of the user.

Agree 100%. But that's how it works. Just wanted to warn you about this behaviour.

In the original post there is a zip file with a GPX, and a few Waypoint from where the CEP was started (in simulator mode) I recently was able to reproduce the same problem, but now on the latest Firmware of the XT and the latest maps.

[smfollen]

@FrankB Thanks, that is a good point but in my recent case all points are properly placed on the intended roads, and are not at intersections. The route does not include any dead ends, u-turns or pizza stops .

...
4. The closest location on the route to the bike's current location was located. This is difficult to prove as when it joins the route, it is then going to pass through the next route point anyway. So some cunning route design and placement of via / shaping points is required to prove that it isn't heading for via or shaping points. Its heading for the route where it is closest. I think that it probably finds the closest ghost point since they are spaced very closely together.
...

@jfheath Yes that is entirely consistent with what I have experienced in the past. When it behaves as expected, CEP heads for the closest via, shaping or hidden/ghost point.

@proofresistant You had mentioned previously that you don't like "ghost" points, or at least the term. The ghost or hidden points are very real parts of routes. They are points taken from the roads or other paths on the map. They get the name only because they are typically not listed anywhere. They are the route point extensions in a gpx file route and are the track points in a track. Yes, for a given route and a track generated from the route, the track points and the route point extensions (aka ghost or hidden points) are the exact same locations. The only differences are how they are formatted in a gpx file and how they are treated during navigation.

I point this out because they do appear to play a role in CEP.

CEP works very well for the next VIA point.
CEP sometimes does not work for the next shaping points.

I think you are on to something again here. For my case, when it goes bad, CEP seems to be ignoring the shaping and hidden points prior to the first via point. Maybe something has changed? Maybe sometimes, for reasons yet to be determined, CEP heads for the closest or next via point rather than the closest via, shaping or hidden point?

I'll keep digging.

[jfheath]

I don't think that I ever published my testing for Closest Entry Point - with the XT1. I got so fed up with it, that although I will use it if I need to, I always have a Via Point to mark the exit from my stopping places - so that I always have a via point to select as the next destination - should I need to restart the route.

Tests were started in April 2020 with version 2.30 of the system software for XT1.

v2.30 headed for closest Via Point.
A later version headed for Via or any shaping point created as a waypoint
Next: any route point, via or shaping - but still only heading for placed route points.
v2.90 was the first to arrive at a good solution - ie the place on the magenta line which is closest the the bike's current position.

This document was created for my pdf version of of detailed notes about the XT1 in 2020. The rest of the document ended up on this forum as a series of web pages. But this particular CEP chapter didn't make the cut !!

If you follow through the tests and the diagrams - you will get a good idea of how CEP works.

I haven't tested any of these findings with the XT2.

[proofresistant]

OK, as @jfheath and @FrankB have written, the cause of (my) CEP problem is the handling of shaping points and resulting U-turns.

If you have U-turns in your planned route as a result of shaping points, whether planned or unexpected, CEP may not work properly and may discard some or all of the shaping points up to the next VIA point.

It gets confusing because my CEP Issue doesn't always happen in the same way.
I observed the following three behaviours when observing the CEP issue:

• CEP works perfectly with some uncalculated imported routes at first, until you recalculate them.
  And then after recalculation, CEP only causes problems.

• CEP does not work at all with some uncalculated imported routes at first.
  And after you recalculate them, CEP no longer causes any problems.

• CEP does not work at all with some uncalculated imported routes.
  How ever you recalculate them or not, CEP problem stay.

What I have found out with relative certainty:

• CEP can find the best entry point between via or shaping points or the track in between.
  (This refers to the whole drawn route line, no matter if you call the individual points of the route track ghost points or not )

• The import flag has no significance.

• The source of the route has no significance.
  (Perhaps those created in the XT2 or Tread app work better, i have not test thoseyet)

• The position and, above all, the viewing direction have no significance.

• CEP always works very well for the next VIA point.

• CEP some times does not work for the next shaping points.
  • I currently expect issues when shaping points result in U-turns.
  • With my new experience, I also think that shaping points placed at ‘critical’ road intersections can be a problem.

• Recalculation can improve it, but unfortunately not always.

• The route planning preference ‘shorter distance’ brings you slightly closer to the next entry point.

Best workaround from my current experience:

• Copy the route so as not to damage the original.

• Just try recalculating the route first.
  Sometimes that alone is enough to solve the problem.
  (For example, that was enough for my XT2, so that CEP then also worked with the problematic route shared by @FrankB )

• If recalculating alone did not help, then I have three possible solutions.
  
  
  • Solution 1
    Switch/change a shaping point into a via point (or adjust the position of the shaping point)
    • Solution 1.1 You still have the critical shaping point ahead of your journey.:
      • 1.1.1: It is best to find the critical shaping point for the U-turn (or even be critical at road intersections also) and change it to a via point.
      • 1.1.2: Find the first shaping point that will appear on your route and change this Shaping Point to a Via Point.
        (It doesn't really matter which shaping point becomes the via point, as long as it is not located after the U-turn (or even be critical at road intersections also) problem point.)
        (Note: I have also like @jfheath observed here that shaping points are extremely manipulated, sometimes even disappearing, when you convert via points (bak) to shaping points in a route using the zumo XT2 device.)
      • 1.1.3: (adjust the position of the critical shaping point for U-turns (perhaps on your PC), but this is probably rather difficult during the tour ).
    • Solution 1.2 You have already passed the critical shaping point during your journey.:
      I recently recognised this case and unfortunately have not yet found a good solution.
      • 1.2.1: It is best to find the critical shaping point for the U-turn and change it to a via point.
        Now I think you will be forced to find the critical shaping point and it is probably necessary to change this shaping into a via point (if its position is not to be optimized).
        • 1.2.1.2: Find the first shaping point that will appear on your route and change this Shaping Point to a Via Point also.
      • 1.2.2: (adjust the position of the critical shaping point for U-turns (perhaps on your PC), but this is probably rather difficult during the tour ).
        Edit: The shaping points on the route before my current position do not appear to be of significant importance.
  • Solution 2:
    Change the routing profile for U-turns and recalculate the route.
    (Note: As I have observed, the XT2 may behave differently from the XT (1).. Currently i cannot see any noticeable effect when I try out @jfheath's tip.
    
    • Solution 2 for a zumo XT2, avoid U-turns [X] mark this checkbox as marked in the Routing Avoidance menu.
      (Please note that with this solution, which I do not consider optimal, you will never reach the shaping point that may have been specifically planned.)
      I probably need to revise my assumption for ‘solution 2 for a zumo XT2’ because I can no longer reproduce it with positive results. So now I think that allowing or avoiding U-turns has no effect.
    • Solution 2 for a zumo XT (1) (Suggested like quote @jfheath), allow U-turns [_] unmark this checkbox as unmarked in the Routing Avoidance menu.
  • Solution 3:
    Try to create a new route from the origin track, which you hopefully have as a backup.
    But then don't navigate to CEP, navigate to the end of the route.
  • Solution 4:
    Let the XT2 optimise the placement of the shaping points.
    But be careful, because this will also change the route to a greater or lesser extent. During testing, I noticed that when I changed a shaping point to a via point and then changed it back to a shaping point, ‘all’ shaping points (in the Section?) were slightly rearranged and some were even removed.
    This had the positive effect that CEP found the next entry perfectly in my previously critical route.
    Unfortunately, a few hundred metres were driven differently than planned, and a detour into a cul-de-sac (may Pizaria ) or a small valley can be lost if a fixed via point was not set before.

[proofresistant]

Unfortunately, I have also noticed that my previous experiences seem to be correct when critical point(s) are still ahead of my journey.
Unfortunately, it may also be that I have already passed critical point(s) and then need CEP.
This is a new challenge that I am now researching.
I am trying to update the previously created ‘guide’.

[proofresistant]

Unfortunately, it may also be that I have already passed critical point(s) and then need CEP.

The previous points were a misinterpretation of my current experiences.
What was previously on the route is not effective (normally) after all.

However, road intersections also seem to play a role when shaping points are set in such a way that the XT2 ‘does not like’ them.

I am now adapting my previous post with the guide based on new experiences.
Soon I will also have a critical route to play with (feel free to let me know if you would like such a demo route).