Edit Route

[Gefreiter Senf]

I have recently bought a Zumo XT, coming from a BMW Navigator 5. On the Nav 5 if I was navigating a route and came across a road which was closed, I would simply select "Detour" and it would recalculate a route which would avoid the closed road. On my first trip out using the XT, using a route I had made I came across a road which was closed. I selected "Edit Route" and then "Avoid the next 1 mile" I won't bore you with the full details, but it didn't work and as I Knew the area managed to go around it and it took ages for the XT to catch up with where I was going and select my diversion, it kept sending me back to the closed road.
So I decided to do and experiment with my friend who has also just got a new XT. I made a route out and designed it so we would stop at a point where we would "pretend" a road was closed. I selected "Detour by Distance" "Avoid the next 5 miles" He selected "Detour by Road" and selected the road we were coming on to. The point where I stopped there was a clear choice of a new route to avoid the "closed" road, the new route ran parallel with the original route. So, both XT's went through the "recalculating" mode, we then looked at the map of the "new" route and nothing had changed ! Still taking me on the planned route.
I have come to the conclusion that the "detour" options on the XT does not work.
Am I not using it correctly ? And what do other people do when they come across a road that is closed ?

[jfheath]

That is interesting. I hadn't come across that particular issue before.

It seems that there are a few routing issues with the XT - from my own observations and from comments that I have read from others.

Unlike the Zumo 590 and 595, having the Zumo set to select 'Fastest Route' seemed to be the easiest way to predict which road the Zumo would navigate if it needed to recalculate the route. Now I am unable to predict how it will behave.

Based on a few simple tests that I have carried out
It appears that 'Fastest Route' doesn't always select the fastest route.
'Shortest Distance' doesn't appear to always select the shortest distance.
In my tests it appeared to show a preference for main roads even when they resulted in a greater distance and/or a longer time.
Hardly scientific proof, but my own observations from a few simple tests.

One issue that I came across the other day was that I opted to not follow the route that it had calculated and instead headed off in a more direct route. It repeatedly tried to make me turn round and go back to the junction where I left the XTs route - even after a few miles when the route ahead was faster and shorter than the original. It didn't give up on that until I was about a mile from where my route and the original joined up. There were no other route points plotted along the route that it was trying to follow.

From conversations with the support team, I get the impression that Garmin are working on a number of routing issues.

I'm sorry - I don't know the answer to your question.

The step from the 590 to the 595 and the step from the 595 to the XT have introduced a couple of massive improvments, but they seem to have introduced a whole lot of other issues that I haven't yet worked out how to deal with.

[Gefreiter Senf]

I have also experienced the routing problem you described with the XT. I deviated from my route about three miles before my final destination (testing the XT), it kept trying to send me back to the route until 1 mile before my final destination before it re- routed me. Frustrating to say the least as I am trying to get to grips with it before my Spain/Portugal trip next year.

[jfheath]

I have to admit that the routing is leaving me confused as to what the programmers are actually trying to achieve.

There are a few foolproof tricks involving routes and tracks that you can use to keep you sane for your Portugal Spain trip.

You might find this link interesting. The result of tearing my hair out for a year with the XT. The problem that you described in post#1, I never even thought about trying - I thought the detour was a good idea on the 590, tried it and was not impressed. I've never used it since on the 590, 595 or XT.

viewtopic.php?t=1464

Section 7 deals with use of tracks to help keep you sane.

If you do not use the Explore.Garmin website to plan trips, then I recommend disabling it. That is also explained.

Thanks for confirming the re-routing back to the original for me - I've been looking for explanations - anyhting that I might have done to make it behave like that. Fortunately I took a load of screen shots as it was happening.

[Fxwheels]

I have exactly the same detour problem with 396. Funny, but it kept routing me back to the closed route, no matted which detour type I selected.
I just looked at the area map and and went by it. Garmin was going crazy navigating me back to the closed road, but in the end connected the route. And I wish it was the only problem with the nav.
My Zumos 396 has not been good when it comes to navigating custom routes and in its ability to handle the issues that may arrive during the trip. On the latest ride it wanted me to make a turn where there's "no turns" sign was posted.
I have an impression that the programming was outsourced then rushed the unfinished unit into production.
Going on a long trip you must have a different and proven nav to run along the XT, or at least as a backup with the same routes loaded.

[Fxwheels]

Note: JFheath edited my post and made it PC, lol

[colirv]

Just for clarification, are these routes created on the XT itself, or are they imported from Basecamp. I imagine importing routes from Basecamp onto the SD card, then importing them into the XT, would give you the option of having a go at your own detour then picking up the route, or re-importing it, to rejoin it at the nearest point.

[Gefreiter Senf]

I made the routes with Basecamp, then as you say imported them to the SD card then to the main memory.

[jfheath]

That is probably the safest way to do it at the moment. Unlike routes sent to internal storage, the routes that are transferred to SD card cannot be overwritten by subsequent transfers. They will always be there to allow you to delete them from the XT and re-import the originals.
Any saved locations or waypoints or favourites (whichever term you wish to use) are also permanently available and they can be deleted from the XT and re-imported from the XT screen. But you have to have at least one point saved in internal memory in order for it to be able to locate them !
(Thats OK you can add one from the map screen if you forget).

None of which explains the odd behaviour you describe. The best way I that I have found is to plot the route in Basecamp. Create a track. Display both on the screen and then get the XT to recalculate the route. This can be done by laoding the route, change the route from faster time to shorter distance and back to faster time. Look at the route on the XT and see if it differs from the track. If it does, add extra shaping points to pin it into place. Repeat.

You may need to delete old routes from the SD card GPX folder - otherwise you will have numerous slightly different versions of the route, all with the same name.

As for navigating. I found the detour did something, but exactly what was a little too unpredictable on roads that I knew to be of any use to me. Sometimes a paper map is required in order to find a road away from the planned route. You can always restart the route from a new location. Take a look at the various options that I mentioned in section 7 of that previous link. One or two will be of interest.

A useful trick is to create a track and use it to 'fly' the route in Google Earth. Get familiar with the roads, scenery and junctions. It is quite interesting how much you remember when on the road. If you want details of how to do this - you know where I am ! Send me a Spain route, I'lluse it to show you how.

[Gefreiter Senf]

jfheath, thanks for all the advice and tips, very helpful. I must say your article "Zumo XT and Basecamp- Everything you need to know" is excellent.
I forgot to add on my original post that when you select just a "destination" no shaping or via points the Edit Route "Detour by Distance" and "Detour by Road" seems to work ok, it's just following a Route it's a problem. So I think the software developers need to do some work on it.