XT routing madness

[colirv]

Thanks, John. My apologies, I phrased my question badly. My setup is as you describe, and my XT shows me traffic problems ahead with estimated delays. I have yet to see a road closure announced, but it didn't occur to me until just now that that's probably because I always plot my routes, in the uk at least, to avoid them! Causeway one.network is my friend.

So my guess is that, if there's a road closure ahead and you have the XT set to recalculate (which I don't) then the XT will do as people above describe.

[jfheath]

So my guess is that, if there's a road closure ahead and you have the XT set to recalculate (which I don't) then the XT will do as people above describe.

My experience - Recalculate allowed or not - if it reckons that the road is closed, it will find a way around it. Which is brilliant if the road is actually closed. A real pain if the road closure is only a temporary traffic light delay (which some have been for me).

[Peobody]

My experience - Recalculate allowed or not - if it reckons that the road is closed, it will find a way around it. Which is brilliant if the road is actually closed. A real pain if the road closure is only a temporary traffic light delay (which some have been for me).

Yup. I have recalculate set to 'Prompt' yet a detected closure can result in a recalculation around it. OTOH, detected delays will result alternative routes being offered. In my experience, the accuracy of the traffic information has been poor so judgement remains paramount.

[colirv]

I have taken to having the track present on any route that I'm following. "Road closure" might be another occasion where that comes in useful!

[Peobody]

"Road closure" might be another occasion where that comes in useful!

There is no "might" about that. It is a valuable resource for determining a way around the closure and back to the route. Detour signs tend to route over the largest roads in the area which may not be the shortest or easiest way around.

The most annoying thing to me is the automatic calculation of a route around a closure and then the recalculation of the remainder of the route. Garmin doesn't give us a choice, like we're incapable of finding our own way around.

[rbentnail]

The most annoying thing to me is the automatic calculation of a route around a closure and then the recalculation of the remainder of the route. Garmin doesn't give us a choice, like we're incapable of finding our own way around.

Actually there are several choices, I've used both with great success:

since I'm generally more intuitive than the XT- stop the route. I'll restart it once past the closure; or the ever popular:

since I'm generally smarter than the XT, having the Auto Recalculation turn off or choosing no when prompted. It'll have changed nothing when you re-join the route.

It doesn't hurt at all to stop trying to make it do something it is obviously incapable of doing. These ways there's no recalculation of the remainder of the route either. Let's face it- if we are capable of finding our own way around then we wouldn't need a gps to begin with, now would we?

[Peobody]

I run my XT with Auto-Recalc set to Prompt and I have twice had it calculate around a road closure without an affirmative response to a prompt. I have spoken navigation turned off so it's possible that I missed a verbal and/or on-screen prompt. If I did, the default response but be the affirmative option. Regardless, my point is that it can calculate around a closure regardless of whether you have Auto-Recalc enabled. Unfortunately, when it does this, it recalcs the remainder of the route. Getting beyond the closure and then restarting the route is the way to recover if the recalc changed the route. The XT can serve as a map so using it to manually navigate around a closure is an option, at least for anyone comfortable with doing so. If the XT gives us the option to not calculate around a closure then I've missed it, twice.

[jfheath]

That's correct @Peobody. If you have Traffic on and it thinks that there is a road closure on the route ahead, then the route is recalculated. There is a brief message I have glimpsed - I think on the banner - but it is easy to miss and you cannot prevent it.

One thing I discovered recently is that 'on the route ahead' (my words) should actually say 'in the current segment' - a segment meaning up to the next via point (or Stop as Garmin are now calling them). It doesn't seem to look beyond the next Stop.

There is a lot of info available on the XTs' screens about traffic if you know where to click. I gathered a load of screenshots recently to prepare a write up. Must get on with that....

[danham]

JF,

This reminds me to comment about "phantom" road closures. I encounter a recurring one on Interstate 84 in Connecticut. It has popped up frequently for the past two years and having ridden and driven that route numerous times, I guarantee it is not closed. What I can't recall at the moment is whether it appears only in pre-planned routes that include that segment of 84, or only when I ask the XT to give me A to B routing that includes it, but my impression is that it does not appear in both types of route.

Because it pops up on a somewhat hectic section of 84 I haven't been able to do any diagnosis on the spot while driving, but ignoring it seems to work without having to restart the route or do other tricks.

So what do we know about sources of closure data and how the XT handles them?

-dan

[jfheath]

Not a lot about sources of data. I guess that there is a data stream coming into the phone and relayed to the Zumo. I am guessing this data is very discrete / digital :- Either a road is closed or it is not, and the roads that are closed only overnight (say) cannot be coded. Someone has to get hold of the information and decide how to code it. People make mistakes.

If a road is coded as being closed, the the Zumo regards that part of the road as being un-navigable. Just like the nearby stretch of moorland. Ignore the instruction and go off road, you get the dotted straight line to take you to the nearest point on the route that is navigable - ie back on tarmc; back on roads not affected by closure.