Acquiring Satellites issue

[Peobody]

I haven’t used any downloaded routes on the unit yet - just simple type in a destination and go. In saying that, the unit seemed to behave itself having placed U-Turns in theAvoid section.

The XT excels at getting you to a destination. The frustrations that I know of are associated with trying to get it to follow a pre-planned route.

You do not need to worry about RUT when creating the route on the XT itself; it will never occur on those, only on imported routes. Preventing RUT involves modifying the route file in such a way that the XT thinks the route was created on the device. Forum member @FrankB gets the credit for figuring that out.

[lkraus]

The XT excels at getting you to a destination. The frustrations that I know of are associated with trying to get it to follow a pre-planned route.

After years with the 590/595, and @jfheath's help, I have no problem getting the XT to follow a pre-planned route. Mostly, that is a matter of preventing recalculation, and using an understanding of how the XT works to create a reliable route in Basecamp.

I can rely on the XT to find a way to reach a destination. But I cannot rely on it to find the fastest route, or the shortest route, or to efficiently deal with traffic slowdowns or a road closure.

I am extremely careful to keep the XT from (re-)calculating a route, because it does that very poorly, often picking routes that are neither the quickest time nor the shortest distance. It favors what it considers "faster" roads - highways, multi-lane roads, major thoroughfares - even if they have more traffic control devices, heavier traffic, and lower speed limits. It will route me miles out of my way just to use a short section of a "faster" road. It is equally bad at re-routing to avoid traffic and construction.

One afternoon, it re-routed me to avoid a "closed" exit ramp that had been temporarily closed 11 pm to 5 am, and had been fully re-opened weeks earlier. Set to prefer Faster time, the normal route was 6.4 miles, 9 minutes. The XT detour: 5.4 miles, 19 minutes, through a congested university campus. Available alternative: 6.5 miles, 11 minutes.

The XT has tried to send me through town on residential streets when there were shorter alternatives that bypassed the town on lightly travelled 55 mph roads.

Yes, the XT will get you to your destination, eventually. But I do not like its choices.

[Peobody]

Yes, the XT will get you to your destination, eventually. But I do not like its choices.

So here is a question... I have only used the XT for destination-only routing a couple of times. In those case I did not notice anything that I thought was surprising about the routing. Otoh, recalculations of pre-planned routes has been terrible. Is there any sense that a recalc produces different results than had we started a new route with the next Via point as the destination and hit Go?

[lkraus]

If you load (or re-load) a well-planned route and select one of the via points as the start, you can trust that the XT will follow the remaining portion of the planned route. It will only calculate a new route segment to that via point and will not recalculate the rest.

I don't trust any recalculation of the planned portion of the route. It is mostly the changes due to traffic or construction that have caused me trouble. If possible, I will stop the bike and find my own detour to get back to the route.

Perhaps I am more sensitive to the XTs poor choices because the worst of them have occurred locally, where I am already familiar with the roads and traffic. I know there are better choices. If I were in a different city I might not be aware that there were better options. Ignorance can be bliss.

For long trips, I sometimes use the XT in the car (with the car mount) because I like the display. I also will use Google Maps (with downloaded maps) on my phone, because I trust the traffic info to be more current and suggested detours to be more sensible. For everyday driving, I just use Maps and leave the XT at home.

[jfheath]

I have only used the XT for destination-only routing a couple of times. In those case I did not notice anything that I thought was surprising about the routing. Otoh, recalculations of pre-planned routes has been terrible. Is there any sense that a recalc produces different results than had we started a new route with the next Via point as the destination and hit Go?

That observation about routing to destination was one of the things that made me investigate the difference between routes planned on the Zumo and routes planned outside. Which led to the understanding that a recalculated imported route behaves very differently from a Zumo built route. (It seems to behave more like a trip that has been converted from a track.

On the way, I noticed something that I have never fully investigated. The effect of using a shaping point and a via point on the route itself. Excuse me for not remembering the details exactly but it something like

V S S S V S S S V

A route of shaping points with one Via point. The middle Via point is intended to force the route over a particular road, and continue from there - a nice continuous flowing line. Of course, it doesn't do that - it reaches the Via point, then doubles back on the road I have traveled to pick up a different route to the next shaping point.

Change it back to a shaping point - the route changes back to the original linear plot. At first I thought it was due to the moving shaping point behaviour when changing Via to Shaping on the XT screen. But I disproved that.

Routes that are 'select destination only' are very quick at re-routing if you deviate.
But so are RUT proofed routes. The addition of any route point will limit the Zumos ability to come up with an alternative.

---------

In the XT2, some recent tests have shown that in an imported route (gpx file), the Via points are fixed, but the route between the Vias, seems to be redrawn vaguely along the line of the original - seemingly ignoring the shaping points that you plotted. The new line has new shaping points in different places. The end result isn't bad, but if you put in shaping points to avoid a particular section of road, it is annoying to have them replaced.

But it only seems to happen if the XT2 is able to synch with the Tread App. If you turn off BT, it doesn't happen and behaves perfectly.

[Iantigerman]

That’s it. I have had enough of this crap Zumo XT.

I went on a simple 30 minute ride, where I entered just one destination. I know the route very well, and just wanted to make sure the navigation of the zumo would agree, or be very close.
Despite agreeing and showing the route and time to go, within half a mile of home, it started with the ‘Make a U-Turn and turn left’ when I was in a high street and on the correct route. It then corrected itself, but tried this subterfuge a few more times e route, plus despite travelling down a road, it seemed to take ages for the unit to ‘catch up’ with where I actually was!
Coming back it suggested I turn down a cul de sac, and at one point tried to take me back to the beginning!
Can you imagine the chaos this unit would cause if I went on an EU trip on unfamiliar roads?

It’s going back to Garmin and I will put the 395 M back on, which has never caused any problems when touring.

[FrankB]

That’s it. I have had enough of this crap Zumo XT.

Too bad. I like my XT a lot.

You could try this: Settings/Traffic
Traffic (Compatible traffic etc....) => Disable
Optimize Route => On Request
Traffic Alerts => (Off)

Now perform a cold start. Hold the power button until it asks: Turn off the device? and reply Off

Next start will take longer (hence cold start) and retry your route.

Of course if you're settings are already like this, you're out of luck.

[jfheath]

That going down a side road to turn back is probably because you have 'Allowe U tutns' turned iff.

If you are heading in the wrong direction, then it is the Zumos job to turn you back. You have got to understand that requiring you to turn back is often the way to get you onto the faster route to your next route point. Eventually, if you persist it should recalculate a new route.

The only things that the XT does that your 395 didn't are
i heads for faster roads rather than the roads that you like to ride.
ii Occasionally, under certain circumstances, it might get stuck in a loop of navigating to the last instruction point. But for that you have to have done something odd - only one of which is deviating from the route.

My guess is that you are not fully understanding how to build and create routes that are foolproof.
Post a copy of your route - the gpx file. Let me take a look. Send it private message if you do not want it in a public forum.

After I may ask you to do some other stuff to work out what is going wrong so that you can fix it. But here's the deal. You follow this offer through, I'll help you sort it out. But I may need you to get me that extra data later on.

I think you are doing something odd, but I'm not into being right or wrong - I'm into helping people understand the problem.

I have the 590, 595, XT and XT2. In order of reliable routing and usability I rank them in that order. But I have now removed the 590/5 cradle from my bike. My preferred Zumo from all of them is the XT. It does exactly what I want it to.

[Iantigerman]

Thank you for your offer of help - it is appreciated.

However, I have ensured that ‘U Turns’ has been set to ‘Avoid'.

If I set a known location into the 'where to’, and it shows a route that I am familiar with ad have used several times, I expect the Sat Nav to take me down that route. The XT doesn’t do that. It will suddenly want to make a U Turn for no reason, and as stated even try to direct me into a Cul de Sac! This happens when I am following the set route and have not changed anything.
I have not downloaded any .gpx files as yet, only simple ‘take me here’ one stop routes. There have been many suggestions of tweaks to do this or that, but to be honest that is not what I expected to have to do with a modern Sat Nav. It should be simple to use and set routes. The XT seems to be nothing like that.
I am not a ‘newbie’ to Sat Navs - my first venture was with a Garmin Street Pilot 3 in 2006 (aerial, no colour or touch screen!), and it worked well and in EU with no issues (well, except for the time took to calculate a new route.. lack of satellites then!). I have not used any other make of Sat Nav because I have been happy with the Garmin make. Until now.
I really don’t need anything that is too complicated, or which seems to have a mind of its own.
I will stay with the 395 LM until I read that the XT has been sorted out.

[jfheath]

Thank you for your offer of help - it is appreciated.

However, I have ensured that ‘U Turns’ has been set to ‘Avoid'.

If you Avoid U turns - ie U turns are not allowed - it does not stop the Zumo from trying to get you to go back the way that you came ! It will use side roads, laybys, housing estates. etc to find a way to trun you back. It may use a culdesac - because that isn't considered a U turn. How else are you going to get out of a culdesac.

Part of the issue will likely be mapping errors. I have seen such situations where the satnav is wanting me to go into a small housing area which has an island in the middle. No reason for it - leave the main road, do a 360 degree circuit of the bit of grass in a horseshoe of 6 houses and then back onto the main road. That has got to be a mapping error. The XT cannot do anything about those.

Let me check how it phrases it: Settings->Navigation->Avoidances->U-Turns : Make sure that there is no tick in there.
The unit asking you to perform a U turn is an indication that something is wrong - and they happen a lot more frequently than the other ways of turning you back - so you get the warning early on.

But if it is a simple route with just a destination AND you do not devviate from that route. It should not be asking you to perform a U turn.

If you allow U turns then a few things may apply if it asks you to perform one.

1. You have missed a route point - or a route point was not accurately placed (but you say that its just a where to? route)
2. The Zumo has not recognised that you have passed the start point. eg you set off in a slightly different direction
3. Your maps are the issue. What maps are you using ? Have you installed additional maps such as the Open Source Maps (OSM).
4. You are not actually following a route - (although it sounds as though you are) - eg if you convert a track to a trip, the behaviour is different and that is also capable of displaying the repeated U turn issue.
5. You were facing the opposite direction from the way that the satnav thought you were facing (very common error) when you set off.

Whereabouts in the UK are you ?