Zumo User Forums

3. Summary

It can be very difficult for me to deny something that I believe to be true. I'll talk about me as I don't want to offend anyone - but I suspect that this applies to most people. It is very difficult for me to get out of my head what I believe the satnav to be doing. It takes a big effort to say , "Hang on a minute, what if I am wrong about what the satnav does".

No, I don't do that. Especially not lost at 70 mph. It is much easier to curse the satnav.
Consequently I make my observations fit the model inside my head. I'm wrong, but I don't even consider that possibility. Not for a moment. Its the map, its the Zumo. It may well be either of those things - but the same symptoms can occur in other circumstances.

There's a good example of this that you can try yourself. Create a short simple route, two points, a start and an end. But place the start on the road where you live but in the wrong direction. Put it 100m behind you. Load the route and set off. Do not pass through the start point. Ride the route and notice what happens. The route is plotted ahead of you but you are being asked to take roads to the left or right, or perform u turns. Turn u turns off and see what happens.

You probably believe that you started the route and that you are navigating it. Apart from the fact that I told you to put the start where you wouldn't pass through it, you probably would stick to that belief. In the meantime, the satnav is trying to take you up all sorts of side roads - simply to do what you asked it to do - navigate a route from the start. It is trying to get you to go to the start.

It is quite revealing, and when you see it on an actual ride, you will recognise that you are not following the satnav's route. The satnav is still trying to get you to visit the start. Notice that the magenta line is dull. If you were on the correct part of the satnavs route it would be bright. No it is dull becasue you are on the section of route that it plotted in order to take you from where you were when you got on the bike, to the start point. You are on the section of route after that. Tap the skip button to see where it is trying to take you. This is actually best done in the passenger seat of a car with someone else driving. Pressing Skip like that reveals the route point that it is aiming for. It certainly isn't aiming for the end point.

That's not to say that the satnav doesn't get it wrong. Maps can be wrong. Road works can be wrong. The symptoms that I described above for the missed start can also apply to incorrect mapping. Road closure information. Slightly mis-placed Via Points.



Heading for faster roads is a pain. It requires roads to be coded into the map date correctly. I have a theory. Not proved. Suppose there are two ways to get to the next route point. One is to ride the nice flowing twisty road to reach the route point 10 miles away. The other is to head for a faster road on a route that totals 18 miles to reach the same end point. I suspect that if the faster road is closer than the next route point, it will head for it no matter what. So in this case if the fast road is 9 miles away and its another 9 miles to get to the route point, it will take the 18 mile route. If the faster road is 11 miles away followed by 7 miles, it will take the 10 mile flowing road that I want

It's not a theory. It is a notion. I haven't even tried to test it. But I have obsereved and I think that something like that may be happening.


Finally

Any gpx file or file sent from Drive or shared via BT is regarded as imported. Any route created on the XT is regarded as saved. Only imported routes behave like I described in section 2 - after skip has been pressed. Routes created on the XT do not behave like that.

There is a way to make the XT treat imported routes as saved. One way is to load the route, say Go! and then back out and save the active route. On the XT this adds a new point (where you are now) ahead of the start. But if you load that new route and start it at the original start point - it behaves like a saved route.

There are a couple of program which @FrankB created that flags an imported route as saved amongst other very interesting tools:

• TripManager (Windows Only)
• Trip Manager with all Options

And a link to the JaVaWa resource here

jfheath wrote: ↑Fri Feb 21, 2025 8:19 am There is also a program that @FrankB created that flags an imported route as saved. Links to follow.

John, I would aprreciate it very much if you would also mention TripManager. (Works only for Windows)
viewtopic.php?t=3150

Or the link containing all the options:
viewtopic.php?t=2301

@jfheath

Talking about links. I suddenly remembered something I noticed weeks ago, but forgot to mention.

On this page: app.php/ZXT-P102 there is a link to a program that doesn't work. www.javawa.nl/triprepair.html
And forgive me my nitpicking, but it's all about giving credits to the right person. That program is created by JaVaWa, based on a Java program I made.

Hi @FrankB

Thanks for those. I've got a lot of links to put in those three replies. It is always fraught with danger trying to do that on the ipad - so I left them until I could get to my PC this morning. I'll correct the attribution too.

The link. Oh goodness - I hadn't spotted that - thank you. The link was correct, except I had not put http:// in front of it - so of course the forum software has made it relative to the website. I have to hand code the html on those XT pages. I wonder if I have made that slip up elsewhere as well. Hmm 100_ pages to trawl through. I'm just going out. I may be some time !!

epv wrote: ↑Fri Feb 21, 2025 1:20 am I was hoping you'd chime in, as you seem to be a Grand Authority on how these things work!

Thank you - but I just try to find things out. I don't for a moment think that I know how these things work. I know what happens sometimes in certain circumstances. Often that is good enough. I sometimes wish I didn't have the urge to find out. Some people do crossword puzzles !

epv wrote: ↑Fri Feb 21, 2025 1:20 am jfheath:> EXCEPT if you join the plotted magenta line that is drawn on the map after the shaping point that you have missed, it will carry on navigating ahead and forget about the missed shaping point.

Ahh-- so if the destination is right next to you might not have enough distance to travel toward it before it decides you're on route again and forgets about the missed shaping point.

I don't know.

I'll make some relevant comments instead. The XT takes one route point at a time. If it is following a route in normal navigation mode - ie point to point, it doesn't seem to acknowledge any route point beyond the next. So if you are coming up to a shaping point followed by a Via Point. it will not announce the Via Point until it has passed the shaping point. Even if it is within its normal range. You will notice the magenta line changing brightness as you ride. The bright bit is the section of route that it is looking at.

If you are on the bright magenta line and you manage to join the route after a shaping point, it will navigate ahead as soon as you rejoin the magenta line.

Here is a video of me missing out three shaping points.

I am supposed to turn right onto Brown Bank Lane. This is a narrow road that heads over the moor before it joins the main road A65). It has three shaping points in it to keep it on the narrow lanes. I am going over the moor on the main road (A6034), and the plotted route will join me from the right at a roundabout. I have turned off automatic recalculation. When you do that two things happen. The route is not recalculated. The navigation voice goes silent. It goes into a sulk because you are not doing as it told you.

Watch what happens once I am facing the right direction on the magenta line.

epv wrote: ↑Fri Feb 21, 2025 1:20 am I wonder if this explains one of the results I saw. I put my destination on the opposite corner of a nearby city park, and a shaping point on one side. So it's equidistant to reach the destination whichever side of the park I follow, but the shaping point is of course on only one side. If I set out from the starting point, follow the line, pass the shaping point, turn to reach the destination, all good.

If I set off from the starting point along the other side of the park, missing the shaping point, it continuously directs me back to the shaping point, devising weirder and weirder ways to get there, even after I've reached the route's final destination. It never realizes I've reached the destination at all, and never asks me about skipping a shaping point. (this happens with both routes created on the XT and routes created on MRA and imported, not unexpected)

From what you just describe, it sounds like just reaching the destination doesn't count - unless you reached it from the direction of the previous shaping point, even if you missed the shaping point. To me, this is insane behavior, but I guess it's a design choice!

Yes - You are correct. You have to be on the magenta line and established as heading in the right direction before it acknowleges that you are OK even though you have missed shaping points. Like when I join the route having missed 3 shaping points int he video above - it waits until I have turned the corner and have been moving in the correct direction before the route changes to a bright magenta and the voice speaks up again.

I only became aware that Via points have to be reached from the direction of the route a couple of years ago. I was testing RUT behaviour and skipped an early point and my route recalculated - taking me a completely different way. I went the way that I wanted - approaching the mid point Via in the direction of my original route. So I checked. I turned the bike round after half a mile and went back to it. Then it accepted that I had reached it. It makes sense - but until then I thought that a Via Point was a Via point that could be approached from anywhere.

I don't know if that means that once the route has been calculated by the Zumo, whether any future recalculations are restricted to entering that Via point from the correct direction.

epv wrote: ↑Fri Feb 21, 2025 1:20 am I don't have much love for google but sometimes I just throw up my hands and wish it could just work like google maps!

I have a real mental block with google maps. I find it difficult to get into, it doesn't produce what I want, and its plots and Garmins differ considerably - not always enough to be noticed - but sometimes. It's not that I'm a luddite. I just don't like the interface, it is not intuitive and I don't have the incentive to use it very often. I spent my whole career learning how to use software and being able to teach it. I know what I have to do, but I really cannot be bothered with it. It's nice to see it on the car satnav from the phone with its 3d buildings. But the satnav navigation that they put in cars is very poor compared to Garmin's.