Unable to calculate path

[Milu23771]

Hello everyone, I recently purchased a Zumo XT and when I want to navigate an imported route from Base camp, if I ask to access from the nearest point, it always says "Impossible to calculate the route". I can only log in from any of the Way points, but if you're in places you don't know, you don't always know which one is closest to you. If instead from Base camp I amount the track and convert it into a trip on the Zumo, "access from the nearest point" works, but so in the trip there are only beginning and end, so I lost all my Way points. Would anyone help me? Thank you

[jfheath]

Make sure you have all software updates in place. The current one is v2.90. Earlier versions were very hit and miss with how Closest Entry Point worked. After updating with Express, perform a couple of cold starts and let it start up fully. Then use Garmin Express to try to find any more updates.

Having said that, Closest Entry point seems to reliably find the shortest way to get to the plotted route. It does seem to have issues near to the start of the route, which I think is understandable - otherwise on a circular route it could pick up the last part of the route.

I am not sure, but I think that you have to have at least one point behind you and one point ahead. That was a theory I was working in before CoVid put paid to any more experiments.

Sometimes if you are plotting a route for somewhere that starts a long way away, it may have problems starting the route as it has to calculate a long route just to get to the start point. If you have avoidances to include ferries, and you need to catch a ferry to get to the start, that would cause issues. Similarly at this time of year, some roads will be closed eg high mountain passes. The mapping has such information stored.

Are these using European Maps ? I'm happy to have a look to see if I can spot anything.

[Milu23771]

Thank you for your answer Jfheath. My XT is updated to version 2.90 and all the routes I planned, are test routes of a few km, in some of which I specifically put the starting point in the neighboring country, so that the route passed a couple of km from me, but unfortunately Zumo's answer is always the same. I also realized that often, during the travel simulation, the blue arrow comes out of the path and continues aimlessly, crossing seas and mountains. Also, the few times the simulation works, I see speed limits, dangerous curve alerts, the next turn in the upper left and the distance from it, speed camera alerts etc., all non-existent things when I actually travel on the same roads. He didn't even tell me today about leaving the highway. I really think it's faulty and I'm going to have to contact Garmin.

[sussamb]

Out of interest what map is selected when you look in Settings, Map & Vehicle, myMaps? What is listed there?

[jfheath]

I have seen this behaviour on my Zumo XT

Check your loaded maps - (I see Sussamb has just said the same thing as I was writing).

If you have two maps of the same area loaded and ticked in the MyMap section in Settings -> Map and Vehicle - that will definitely cause this issue.
(eg I have some OSM map loaded for Europe - they are very nice and very detailed but do not contain any road speed data, so timings and ETAs cannot be calculated accurately. If I have that map ticked and my North Europe map ticked. I can reproduce your issue)

Like wise, if you have no map ticked for the area that you are planning the route - the same thing happens.
Eg if you are in Italy and are normally using CN Europe NTU 2021.10 ALL South, and you are planning a trip to France or UK, you may have forgotten to tick the CN Europe NTU 2021.10 ALL North map.

If so, that would also definitely cause the issue that you describe. I have just tried it on my XT.

nb - If you use Basecamp and have not loaded the same version of map onto your computer as you use on the Zumo, then that can cause problems - resulting in long waits for the map to calculate when you load it into the Zumo.
Also a similar thing can happen if you use other mapping software - eg MyRouteApp.
I don't think either of these situation would result in the things that you are seeing though.

[Beszot]

Hi

I had similiar case. Zumo lose all viapoints, when calculated track to routes. Long tracks, with 2000 points, short with 20 - all. Route always had start and end only.
Garmin changed for newone. Worked 1 month, now he started lose viapoints again.
I'm angry - this stuff looks underdeveloped, unreliable, expensive and shitty.
They have big problem with quality of software or something.

[jfheath]

I had similiar case. Zumo lose all viapoints, when calculated track to routes. Long tracks, with 2000 points, short with 20 - all. Route always had start and end only.
Garmin changed for newone. Worked 1 month, now he started lose viapoints again.

It can be frustrating - but don't get angry. I think you are not understanding something about tracks and trips/routes.

A track is just a series of hundreds of dots that the zumo draws on a map in the form of a line. It has a beginning and end and a line. It cannot change, you cannot navigate it. It does not have any fixed intermediate points (like Via Points or Shaping Points).

A route is a small number of points which you want the satnav to navigate. The satnav will calculate a route between each pair of route points and to do that it will use the settings that you have set in the Zumo (faster, shorter, avoidances). Its job is to take you through each of the route points in the correct sequence. It will try to stick to the original route, but if you wander away from the original, it will want to calculate a new route, but still take you to the next route point (Via or Shaping). Your job is to make sure that you have just enough route points to ensure that whatever the satnav calculates, you get to travel the roads that you want to travel.


But - I don't understand why you want to convert a track to a route. Where does the track come from in the first place ?


If you start with a track and convert it to a route (or a trip as the Zumo calls it) - the track does not have any Via Points or Shaping Points in it. It just has a start and an end point. The Zumo plots a route that follows the original track exactly.

Except

It is extremely likely that the satnav will recalculate the route that you are following at some point. If for example you go off the route, or the route (and the original track doesn't go along roads that are known to the Zumo maps. Or if you have features on your smartphone turned on (eg to avoid traffic or road works), and you have automatic recalculation turned on.

What happens then is that the sat nav will recalculate a new route to get you to the next route point (ie the next Shaping Point or Via Point). But in this route that has been converted from a track, it will not have any Via or Shaping Points in it. So it calculates a new route to the only point that it knows: the end point.

Yes - it appears as thought it has lost your Via Points and Shaping Points. But they disappeared as soon as you created a track from your original route. Not when you converted the track to a trip on the Zumo.

It is doing exactly what it is designed to do - to get you from where you are now to where you want to go. And to be fair - it does a pretty good job of doing that, using the preferences that you have set in the Zumo itself - Faster, Shorter, Avoidances etc


To get round all of this, when navigating on the road, you need a route. A route consists of a Start Point and End Point and a number of intermediate points which force the navigation to pass through particular points. If you position these sensibly, the satnav will never go wrong.

So for a route of about 200miles/300km, I would probably have a start, and end. possibly 3 or 4 Via Points which I use to mark the road that I want to be on after I have made a stop. I then use Shaping points to force the route to be on particular roads, and to marks a few likely stop off places, which I can then choose to follow or ignore. Typically there may be about 12 of these. If I am travelling on interesting roads that run in the same direction as a main road or Motorway, I may need more shaping points to stop the satnav from taking the faster route on the main road.

Usually I take the trouble to set most of these points as Waypoints before I start the route. That way, when I transfer from Basecamp, the Zumo keeps the name that I have given to it, rather than replacing it with its own name.

[Milu23771]

Thanks for the exhaustive explanation Jfheath, I had guessed from reading the various forums and tutorials, that it worked like this, but obviously I still make a lot of confusion. Today I will try to redo a path following your tips. I also installed OSMs, but in the last tests I kept them disabled, and I used the TopoActive PS Europe 2020.20 South West on Base Camp, also installed on my Garmin. Maybe I should take a closer look at the Device Navigation and Basecamp settings. I take advantage of your patience for one more question: the recalculation of the route in case of exit from the track, should it be left automatically or disabled? Hi

[Beszot]

Thank you for answer. But you miss the problem .
Story is this:
1. I take TET tracks, long and Full od waypoints. TET tracks are rural, dirt roads. But my First Zumi made router with this on Topo map. With Many, Many waypoints. 300-400 km long , teksty route.
2. I made short Free ride on my own, by dirt roads, forest roads. Track Was calculated by zumo with waypoints.
3. After 2 months i tryed make this another one ... and zumo made route only with start and end.
4. Garmin wanted see my zumo. They replaced with New one.
5. New Zumo worked good two months. Now started calculated tracks/routes again losing waypoints.

Do you understand? If you are from Garmin Staff i can write case number, mails from Garmin etc.

Its not problem with my way of use Zumo xt. Its problem with zumo and actualisation , i think.

[jfheath]

@Beszot

Yes - I missed the problem. I thought you were on roads - the original post seemed to be about road use.

I have limited experience of trying anything on the XT for off road use. The only time that I tried, I could not get Basecamp to produce a route that could navigate off road in the 'normal' way. I conclude that it was only possible to display a track and follow it as you would a paper map. I hope that assumption is wrong, but if it is, I couldn't find the answer - and you seem to have had more success than me. However - I note that there are new Topo Maps available Topo Powersports Europe 2020.20 and iOverlander 2021.50. I'll see what mine does with those. If I can find out how I put the previous maps onto my computer for BAsecamp to use.

@Milu23771

Just in case I have got confused with your problem as well - are you following roads or are you riding off road ?

Regarding recalculation - if you set it to 'Prompt' then you get then you can see when it is trying to recalculate, and you can decide at the time whether to allow it or not.
I am nearly always on road. I have north and south europe NTU maps on the Garmin and these are both ticked. I don't know where 'north' stops and 'south' begins so I tick both, as I have been planning and viewing routes that border northern Italy.

In simulation, the XT wanders off the road if I just have Powsports Europe maps ticked. This map seems to require the NTU Europe maps ticked as well.

No - I am not linked to Garmin in any way. I just don't like using the Zumos unless I can work out how they make their decisions. I don't want to end up in a situation where I am stuck in an unknown area trying to work out how to get to where I need to be. So I carry out a lot of tests. Then, if it goes wrong, I can find out why. I tend to find out things that the technical support staff cannot help with. They seem to like to end discussions about a problem by asking for the return of the unit. Garmin do a very good switch out service, but if it is over 1 year old, it costs. It doesn't necessarily solve the problem though.