I don't have any bright ideas, and judging from the lack of response, neither has anyone else.

All I can say is that Waze doesn't normally route that way. It may be that someone running Waze stopped on the A420 and fooled it into thinking there was a massive traffic jam that needed to be avoided. (Just conceivably there was indeed a massive traffic jam, even though the reporter thinks not).

Maybe there's a glitch in the routing engine which only shows once in a blue moon.

Anyway, I don't think there's anything wrong with the map. BTW when you reply to and close this UR, there's another one a little NW, which looks like it was raised by the same person on the same occasion.

Ian

As Ian mentioned, we were all lacking in bright ideas, however a problem I have been looking at may be related.
I tend to use Waze navigating, even if I am only travelling a short well known route and I am regularly surprised how often it shows up a problem. For the last week I have been trying to find a problem where Waze sends me around the block on the final few 100 yds to get home!! This only happened in the app, and I could not get it to do this in the livemap. Yesterday it suddenly stopped doing this and I realised to could be related to the beta version I was running on Android, as this was updated about a week ago and updated again yesterday. I have no idea if there has been a rogue revision with a problem, in either beta or the released version, but there was definitely something funny going on which now seems to have stopped.
Ian

As the Ians have suggested, this is probably due to either a spurious traffic jam, or a glitch in the (routing) matrix.

Plotting a short route along A420 does have that detour as the 2nd possible route, but that would take an extra 2-and-a-half minutes. I guess a (potentially bogus) traffic jam could trigger that 2nd route. Maybe.

The Detour Prevention Algorithm wouldn't apply here because of the roundabout.

Not-Ian

We don't hear anything about routing engine updates, but I'm pretty sure that one has been implemented because it's now respecting restrictions, which it has been ignoring for the past week or so. I suspect that they messed up the routing engine code and have now fixed it.

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