My first encounter with phantom road closures

[danham]

Peobody,

I see two perhaps separate issues, one of which I think is exactly what you describe.

First is the bogus closure symbol. That may not be due to complexity, though I suppose one of the lower-level roads in that mess might be closed, though I have no evidence of same. Second is the nonsensical recalc route, and I am sure the complexity coupled with some possible position error could be a big factor.

Finally, what the heck is that black line beyond the closure symbol all about?

-dan

[Peobody]

First is the bogus closure symbol. That may not be due to complexity, though I suppose one of the lower-level roads in that mess might be closed, though I have no evidence of same. Second is the nonsensical recalc route, and I am sure the complexity coupled with some possible position error could be a big factor.

The last road closure recalc I experienced produced in a route that was not rideable. The black line is the track of the original route. Travel direction was eastward. The closure was at the bridge over the stream that is visible to the east of the "NC182" marker.

CnP_14112024_141230.png (898.89 KiB) Viewed 561 times

Finally, what the heck is that black line beyond the closure symbol all about?

Did you have a track of the route showing on the map in black? If not, I don't know.

[danham]

Nope, no tracks displayed. I once saw similar bogus closure on I-84 in CT, and it also showed a black line beyond the closure. But unlike my Boston fiasco, ignoring the closure did not affect the route or cause a recalc request.

-dan

[Peobody]

Nope, no tracks displayed. I once saw similar bogus closure on I-84 in CT, and it also showed a black line beyond the closure. But unlike my Boston fiasco, ignoring the closure did not affect the route or cause a recalc request.

I have also been able to ride through some closures, but then others force a recalc. I wonder if there are different classifications of closures. Maybe a closure for repaving will not force a recalc but a closure at a bridge will (traversable vs. not traversable). That feels like a stretch but it would explain why sometimes the XT acts one way and sometimes it acts another. This makes me think of "road closed" signs on the shoulder when the road is open but there is work going on off the road surface. I'm convinced those signs are there solely to alleviate the contractor of liability. I don't know whether those 'closures' would be submitted to the traffic provider of the Drive app.

[jfheath]

We dont have many multilevel highways in the UK. But the exit and entry slip roads run pretty close. If the route is along the motorway, and I take the slip road. It doesn't indicate that I am on the 'wrong' road until I start heading in the wrong direction. If it loses the signal it assumes I am travelling at my last known speed along the plotted route.

I spotted that black line once before - I thought it was a track that I had installed at the time. But it could well have been a 'remnant' of the original route, now you mention it. Does that mean it leaves a trace of the original route for you to follow ??

[Peobody]

Does that mean it leaves a trace of the original route for you to follow ??

That is an interesting question. That black line is thin and appears to be bordered by a faded magenta. I wonder if anyone who shows a track on the map in black would see it. I normally do, and I have never seen it.

[danham]

Does that mean it leaves a trace of the original route for you to follow ??

That is an interesting question. That black line is thin and appears to be bordered by a faded magenta. I wonder if anyone who shows a track on the map in black would see it. I normally do, and I have never seen it.

The magenta is, as I’m sure you know, the original route. The black appears to be layered on top as part of the warning that the road is closed, which of course isn’t.

[Rofor]

@Peobody -

I have also been able to ride through some closures, but then others force a recalc.

As far as we have tracked down this in the german community at Naviboard.de the forced recalc of a route, uninterruptable and nevertheless what the settings on the unit are, always appeared when a complete(!) road closure (both directions) is signaled via traffic information.

First time for me was in June 2020, after the first europe-wide COVID-19 lockdown - one day after the borders between Austria and Italy where open again, we travelled to Southern Tyrol with our motorcycles, using the newly Zumo XT. All went fine and we where in Eggental for nine days. When driving home again around 100km from the border between Italy and Austria the Zumo XT started to recalc the route home automatically without any sign why he is doing this - i only noticed it, because the distance to finish jumped from 150km to 890km(!). When arriving nearly the border of the two countries, i noticed that there was a 'not allowed to pass' sign directly at the border. The Zumo XT has gotten the false information, that the borders between the countries are already closed and had calculated a route from Italy over Slovenia through Hungary back to Austria...

Because why i had no idea at this time about this 'problem', it was really disturbing us and i was thinking about a real failure of the unit itself as i always where using it with a 'recalculation off' setting....

Second time was two years later also in Southern Tyrol when there was an (also false) information of a complete road closure and a following 'silent' automatic recalculation after an enormous thunderstorm. This time, already aware of that problem, i disabled 'Traffic Information' in the Zumos settings and started the route again and bang - after driving a few kilometers the recalculation suddenly was back, even when 'Traffic Information' was turned off!?

Only after restarting(!) the Zumo XT and than restarting the route again, the navigation continues as planned - so it seems that the the Zumo XT has a 'memory' of the last received traffic information, which is only cleared after a complete restart of the unit.

So the fact, that at least here in Europe the traffic information about road closures are not really reliable and the behavior of how this infos are handled by the Zumo XT is the reason why 'Traffic information' is permanently disabled on my Zumo XT...