XT More Observations when Driving Routes.

[jfheath]

In the last couple of days I had a couple of long trips in the car. So I put a route into the satnav and carried out a couple of experiments.

The route was straight forward. Mainly motorways and A roads. I put in a couple of shaping points to prevent it from routing me through city centres and to take me on roads that I preferred. But mainly the Via Points were the stopping places.

I deviated from this route a few times during the course of the journey. On each occasion the XT quickly and effectively recalculated a new route from where I was towards the next route point. This is how it should be, but I have rarely seen it do this on the XT - it has always seemed more concerned about getting me back to the magenta line. In fact it plotted the route that I was taking.

I ignored the second cafe stop, and continued south on the A roads. So I had missed a Via Point. It asked if I wanted to skip the Via Point after I had ignored two instructions to get me to go back. I ignored that as well. The again - two more instructions to turn off the road I was on, and another request - do I want to skip ? Which I also ignored. I just continued driving south. After not responding to the third 'Do I want to skip?' request, it did something that I have never seen before. It continued navigating ahead and stopped asking me to go back. So it Skipped the point itself automatically.

I checked, by pressing the Skip button. The next point ahead was the next Via Point about an hour ahead. I had nor shaping points coming up.

I wondered what it would do if there had been shaping points in between my current position and the next Via Point. Was it simply heading for the 'next destination' - ie next Via Point, ignoring any intervening shaping points. I didn't know because I had no more shaping points.

So On the way home I repeated the exercise - deliberately missing a Via Point, and making sure that I had two shaping points ahead before the next Via. The same thing didn't happen. It kept asking if I want to Skip and I kept ignoring it. Each time it spent longer and londer calculating a route - the further I got away from the missed Via. I let it do this for about half an hour. It didn't automatically skip the missed Via. In the end I touched the screen to skip the point myself - and the Zumo gave up, shut down and re-booted.

I repeated another deviation exercise - simply choosing not ot go along the plotted motorway route. It quaickly calculated a viable alternative - eventually leading back to the motorway. When I ignored that, it plotted the route that I was intending to drive. No fuss, no delay. It was behaving just like my 590 and 660 used to.


Two more observations.

Closed roads were plotted on the map as red circles filled with solid white.
I had forgotten that my avoidances were set to avoid motorways. My route was plotted on motorways. Juust before I reached the motorway, it popped up an information box down the right hand side of the screen, warning that I was about to drive on the motorway. Did I want to do this or did I want to take the alternative route that it described in road numbers. I didn't have chance to take a screen shot. Far too much going on around me.

[Peobody]

It sounds like this experience reinforces my suspicion that the XT is behaves unpredictably when a route contains shaping points. In your case you missed a via point, mine was a missed shaping point. In my case the XT insisted on returning me back the way I came to where I left the route even after I skipped the missed shaping point. It never recalculated to the next point which was the end point. Did yours direct you back as well?

[Oop North John]

Does it make any difference if you're in the Car or Motorcycle profile?

[jfheath]

Does it make any difference if you're in the Car or Motorcycle profile?

The short answer is that I don't know. I want to find out about this, but I haven't found anyone to come up with detailed information about when they believed that the car mode produced better results. I have tried a few times to get it to produce different results, and I cannot do it. But when I do this, I make sure that my Zumo Car profile and the Motocycle profile are set to be exactly the same.

In this case the XT was in the car in the car cradle. But both of my cradles are registered to switch the XT to the motorcyle profile. So the Zumo was foolowing a motorcycle route with motorcycle preferences and avoidances.

I suspect that the issue that people have with this is that they are not aware of a few things that happen.

1) When you put the XT into one of the cradles (it actually recognises the power source), it switches the Zumo's vehicle (Usage Mode) to be the vehicle that was set the last time the Zumo was powered in the same way.
2) Each Usage mode can store different routing preferences - so that is three different stored sets. One for motorcycle, one for Off road, one for car.
3) The route from Basecamp contains information about the Transportation Method. The Zumo XT recognises only Driving, Motorcycling and Direct. If the route contains no details, or it contains a Transportation Method that it doesn't recognise, it defaults to using the Motorcycle settings, no matter which power source or cradle it is attached to.
4) Routing preferences are also specified in the route. If they are not specified, then the XT defaults to using Faster Time.
5) Whichever vehicle the Zumo is set to use to navigate the route, when it recalculates the route it uses the avoidances that are set fot that vehicle.
6) If the Zumo is connected to the car cradle, using the USB lead for its power, and you laod a motorcycle route, the next time the Zumo is plugged into that cradle, it will switch it to motorcycle mode. There are consequences if you are programming your XT at home and you have it plugged into the charger. It may thing that you are in the car. You set the XT to motorcycle mode. The next time you put the XT in the car cradle and power, it switches it to motorcycle.

I haven't investigated whether the XT builds up separate profiles for when it is used in Car mode and when it is used in bike mode - historic behaviour definitley has an effect on how the XT routes.

There are too many variable to consider to take at face value the comment that routing with the car setting produces better results than with the motorcycle setting. It may well be the case.

Garmin say that the motorcycle mode will come up with routes that are different from the routes that Car mode will. I haven't been able to confirm this - either on Basecamp or on any of the Zumos that I have owned. I don't know if it is Garmin speak to explain the fact that the two vehicles store different configuration settings.

I suspect that if you plug a ZUmo into the car cradle and create a route using a couple of route points, Typically the Zumo will use the car settings to plot the route. When you plot the same route in the motorcycle cradle, typically the Zumo is in motorcycle mode, and it will plot a different route because the chances are that the motorcycle settings are different from the car's.

When you transfer a route the behaviour might be different again, because some of the information comes from the route itself.
The Zumo does try to warn of changes in routing preferences and changes in vehicle - but it is not entirely foolproof.

All I can say is that on this route - I just wanted to get there so was happy on motorways and major roads - it was a motorcycle route with my motorcycle settings and it behaved very much like my 590. Very predicatbale - apart fromt he few interesting observations.

[jfheath]

It sounds like this experience reinforces my suspicion that the XT is behaves unpredictably when a route contains shaping points. In your case you missed a via point, mine was a missed shaping point. In my case the XT insisted on returning me back the way I came to where I left the route even after I skipped the missed shaping point. It never recalculated to the next point which was the end point. Did yours direct you back as well?

Mine was a missed via point. It kept attempting to get me back to the Via Point. and then it gave up and navigated ahead.

The phenomenon that you describe that results in the XT repeatedly trying to get you to go back to the last place where it gave you an instruction - I didn't notice that - but I was on main roads and it was asking me to do a U turn most of the time - and you cannot spot the behaviour we have both described when it is taking you back the way that you have just ridden/driven.

However, I did expect it on the return journey where I chose to stay off the motorway. It gave me a number of instructions to take roads to lead me back to the A1(M), but when I ignored them, it did not tell me to go back. It very quickly calculated a new route ahead towards the motorway - in the direction of my next route point (which was about 20-30 miles ahead). This is what I want from the satnav. I have not yet analised why this behaved properly when in the past it has insisted on taking me back the way that I have come. It was a motorcycle route, the XT was in motorcycle mode, using motorcycle preferences. Just the same as always.

The only big difference is that I have many more miles on the XT now - I kept restting it when I was writing those detailed notes about it, so it always behaved like a pretty new unit. Maybe. I don't know. I'm puzzled.

Incidentally. I noticed this week that a local road which I use every day to get to the village, and which stanavs have happily routed me along, will no longer naviagate me for the full length. Closer inspection of the maps revealed that the map thinks that the two ends of the road are no longer joined together. They are both dead ends. Coincidence that a new school has resulted in the road being a new route for pupils to take ? Or perhaps the local action group wanting to stop the road being used as a rat run have discovered that it is possible to inform the mapping organisations that their maps are 'wrong' ? Whatever, it seems to be a new way of traffic management. I don't think that I mind about that, but it begs the questition - how many of these mapping issues could be as a result of similar map 'corrections' ?

[Peobody]

Mine was a missed via point. It kept attempting to get me back to the Via Point. and then it gave up and navigated ahead.

On your outgoing trip you mentioned that the XT behaved as expected but then you said "I wondered what it would do if there had been shaping points in between my current position and the next Via Point. Was it simply heading for the 'next destination' - ie next Via Point, ignoring any intervening shaping points. I didn't know because I had no more shaping points." You tested that on your return trip and the XT crashed. My sense is that the existence of any shaping point ahead of where you leave the route is a common denominator for trouble.

Incidentally. I noticed this week that a local road which I use every day to get to the village, and which stanavs have happily routed me along, will no longer naviagate me for the full length. Closer inspection of the maps revealed that the map thinks that the two ends of the road are no longer joined together. They are both dead ends.

I have seen that on the CN NA map in Basecamp too. A check on Google Maps will show the road as a through road, confirmed with satellite or street view. The next time I encounter it I will try to remember to see if there is anything at the break point that could explain an attempt to discourage traffic. I would be disturbed if map manipulation is going on. The road that would be impacted by this are the kind of roads that I want to be riding on, the roads less traveled.

[jfheath]

Mine was a missed via point. It kept attempting to get me back to the Via Point. and then it gave up and navigated ahead.

On your outgoing trip you mentioned that the XT behaved as expected but then you said "I wondered what it would do if there had been shaping points in between my current position and the next Via Point. Was it simply heading for the 'next destination' - ie next Via Point, ignoring any intervening shaping points. I didn't know because I had no more shaping points." You tested that on your return trip and the XT crashed. My sense is that the existence of any shaping point ahead of where you leave the route is a common denominator for trouble.

No I don't have evidence for that. The two situations were different. I was surprised that after 3 skip messages, that it decided to continue ahead. It displayed the 3rd skip message and then it disappeared as though I had touched the Yes button. I hadn't my hand was nowhere near it, but it could have been some outside effect - those screens are very sensitive, especially when the unit is hot. We were heading south in balzing sunshine. It is a Possibility.

What I wanted to find out is whether it was treating the Via like it does when selecting next destination - and skipping all of the shaping points before that Via. But it didn't pull the same trick. It behaved as normal. I left it doing the skip query and ignoreing it for a very long time, and it got so that it was taking an age to refressh the right hand side bar, the further I got from the missed point. It was as if it was hanging up. In the end, I decided to touch the screen to try to stop it. That was when it crashed. I think it probably just ran out of memory available for processing. (Exceeding the stack size is a common issue when computers get stuck in infinite iterations.)

You may be right about the shaping points, but what I saw cannot be used as proof of anything.

Incidentally. I noticed this week that a local road which I use every day to get to the village, and which stanavs have happily routed me along, will no longer naviagate me for the full length. Closer inspection of the maps revealed that the map thinks that the two ends of the road are no longer joined together. They are both dead ends.

I have seen that on the CN NA map in Basecamp too. A check on Google Maps will show the road as a through road, confirmed with satellite or street view. The next time I encounter it I will try to remember to see if there is anything at the break point that could explain an attempt to discourage traffic. I would be disturbed if map manipulation is going on. The road that would be impacted by this are the kind of roads that I want to be riding on, the roads less traveled.

I think the moral is to not rely 100% on your satnav. There may be other forces at work. We don't want to be riding off cliffs. MY fear of riding narrow roads is that it finishes in a downhill dead end, with no where safe to turn around ! A motorcycle lobster pot. A lesson I learned with my motorcycle and sidecar. Not thinking I rode it up against a wall in a sloping car park, front wheel pointing downhill against a wall. I never thought about it until I tried to set off again. Ah. That was stupid John. It was too heavy to push back.

[fatfeet]

I deviated from this route a few times during the course of the journey. On each occasion the XT quickly and effectively recalculated a new route from where I was towards the next route point. This is how it should be, but I have rarely seen it do this on the XT - it has always seemed more concerned about getting me back to the magenta line. In fact it plotted the route that I was taking.

I went out today and tried to emulate this occurrence, here are my findings.

I planned two short routes only about 5 miles using MRA, one route had via points (hand) only and one also having shaping points (teardrop), although I used the same via points, (reversed route)

The route A to B had via points only , the route B to A had shaping and via points, I carried out a number of trips using various settings on the XT. the black line drawn on the screen shot is the detour route I took each time. the via point on the screen shot is marked to show which one I skipped.

full route shaping.png (781.25 KiB) Viewed 1018 times

full route no shaping.png (801.59 KiB) Viewed 1018 times

test 1 A to B
recalculation off, did not use skip.
all started well, I deliberately turned left onto my detour route, the XT went quiet, I did not hear any spoken instructions again for this route. even when I rejoined the magenta line on the A6, the XT did not restart the spoken instruction.

test 2 B to A,
recalculate off did not skip, this time the route had shaping points.
started good, I turned right off the A6 on to the detour route, again the spoken instruction stopped, when I rejoined the magenta line on the A6015, the spoken direction did not return.

test 3 A to B
recalculation on, did not press skip.
after departing A, I then turned onto my detour route and whithin 2-3 hundred metres the XT wanted me to u-turn and it kept doing this even when I turned left onto the A6, which was actually back on the magenta line, even when I passed over another via on that route, XT did not stop asking me to u-turn, I presume it wanted me to go back to the initial via point I missed.

test 4 B to A
recalculation on, this time pressed skip to avoid via point(marked on screen shot)
after I departed and turned off the A6 on to my detour route, the XT recalculated, initially wanting me to u-turn, I pressed skip next via point, and it calculated a new route along my detour route. all was well until I reached the junction where I should turn right to rejoin route. the XT wants me to turn left. the reason for this, is, that there is a shaping point about 400 metres down this road. I ignored the instructions to turn left. and turned right the XT knew I was back on the route and then forgot about the shaping point behind me, and continued instructions to end of route.
this is fine, as I knew where I was, however, if we are on a diversion route and do not know where we are in relation to the route, we would potentially follow the instructions only to have to turn back again.
if you look carefully at the screen shot, you will see a via point on the right, which is the correct route, XT wants me to visit shaping point left. this is on the original route and a few hundred metres after the skipped via point. if I had followed the original route I would have came from the left.

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test 5 and 6 converted to track-trip on the XT, recalculation on.
I turned off the route A to B and within a few hundred metres the XT recalculated me along the detour route to rejoin the magenta line. On test 6 which is B to A when I turned off A6 on to my detour route, initially XT tried to u-turn but after two attempts the XT then routed me along my detour route. when I reached the junction back on to the correct route it did not ask me to turn left, As happened above, to pass over shaping point it instructed to turn right back on to the original route.

I also carried out using track-trip with recalculation off, it just went silent with no new magenta lines basically I was marooned with no indication of location of my original route in relation to my position.

in summary, the only time in my experiment that emulated @jfheath is on test 5 & 6, after I converted to track-trip.

After pressing skip via point, the XT will still try to send you to a shaping point, but will not insist if you are back on the route, this has the potential to cause you to do a u-turn.

still got a few trials yet, hope some of this helps, I am sure @jfheath has already covered some of this.

there was an amendment to the test 5 and 6 above, I initially wrote, that I pressed skip after turning off the route, this is not an option when using track-trip. I have now removed it from the test findings, My Bad

[jfheath]

Thanks for this @fatfeet.

I know the roads you have plotted - in fact we often use a route throught the Pennines to get N Wales of S Wales, and stay overnight. We like the Packhorse Inn with nice views across to Kinder Scout and Kinder Downfall. And Whitehall Centre which is on the highest section of the A5004, was an outdoor centre (it might still be) and is where I taught Outdoor Activities as a trainee teacher when I was in my 20s .

I've read through and got my OS maps out on the screen and have a good grasp of the tests that you set. That is a pretty comprehensive little route, and plenty of opportunity to practice tight hairpin road junctions. I was relieved to see that the traffic lights are set back at the junction at Newton so that you can use both sides of the road, when we came across it from the Packhorse, heading to Whalley Bridge for the first time in June. (Actually we were trying to get to the Congleton road, but in June the first few roads that we had plotted were closed for road works.

I think that Tests 1 to 4 are exactly what I would expect. If you are confused by that, then I'm happy to explain why in more detail.


Test 5 & 6 and the other Track Trip tests confuse me. You say you converted to a trip (a track-trip) and are running that but you say that skip is available.
Track trips don't have any route points - via or shaping. The have a Begin and an End. and thats it. They should not recalculate, but they will calculate a way to get you back to the route if you deviate if auto recalc is turned on.

I need to study that in more detail.

[fatfeet]

I think that Tests 1 to 4 are exactly what I would expect

as did I, I just thought it would be good to put all my findings on here. others could then gain some knowledge, and perhaps practice a similar test. there is also the potential that someone may attempt one of these tests and gather different info, who knows.
the one thing that is a bit weird tho, with recalculation off, even when you return to the route, the magenta line remains dull and there are no instructions, one would think that the XT should recognise you are back on the route.

If you are confused by that, then I'm happy to explain why in more detail.

Thanks for the offer but I do understand the peculiarities of this machine. I have changed my thinking somewhat, in the way I place shaping points. I used to place an inordinate amount to ensure my route remained as I had planned. the problem we all have is diversions etc, but once one understands how the XT works it will make life a little easier.
in my experiment, when skip was used it only recalculated to the next via, unless there was a shaping point. but obviously this was only a short distance. I will be planning my routes with great care. looking at potential routes the XT may take me if I press skip.
I need to do this experiment with greater distances, this is quite easy round here especially as the snake is now open again, using edale and Woodhead as diversionary routes.

I am definitely going to use either, Track-trip, or just track on my next tour, which is in Austria riding around the alps, and not using motorways in Europe to get to St. Anton.

Test 5 & 6 and the other Track Trip tests confuse me. You say you converted to a trip (a track-trip) and are running that but you say that skip is available. Track trips don't have any route points - via or shaping. The have a Begin and an End. and thats it. They should not recalculate, but they will calculate a way to get you back to the route if you deviate if auto recalc is turned on.

this has got me thinking, maybe my notes had been written down incorrectly, I will pop out again today and carry out the exact same test, in retrospect, I think you are probably correct but I need to know for my own piece of my mind.
I will update on here later, and add any amendments as necessary.