Any route coming into the East roundabout and exiting from the West goes OK.
Any route that comes into one of the two roundabouts and out via the same roundabout and any route to or from the segment between the roundabouts also goes OK.
However, any route coming into the West roundabout and exiting from the East does not route using the link between the two but goes around the houses on a long and unnecessary detour.
I can’t see anything wrong with any of the routing between the segments.
“Double roundabouts” cause enough problems to have a thread of their own. Although to be fair, most of them work. I don’t think anybody has much idea why some fail, but iainhouse is the expert, and will probably find this thread and comment this evening. Or you could PM him.
It’s probably because I found a pair that didn’t work and kept tweaking & rebuilding them until they did. Then tried again. And again.
This is a typical double-roundabout failure. Routing involving on roundabout only works fine, but routing between the 2 roundabouts stops working in one direction only. A pair of roundabouts will work for years and then suddenly stop for no apparent reason.
We really don’t know why and HQ haven’t been able to give a helpful suggestion. It’s not the length of the middle segment, or the size of the roundabouts, or the naming or types of any segments, or any angles, or the number of connecting segments. It is damned annoying.
I have a “standard” method of rebuilding these roundabouts, which I have applied in this case. Give it a couple of days for an update to take effect (for reference, I rebuilt at 11:30pm on the 8th) and see if the routing is fixed.
