Could do with some advice from more experienced editors with something, please!
A UR appeared in my feed at this junction, with the user reporting that they’d been instructed to make a U-turn at the lights to take them back to the east, despite this being prohibited according to the signage here. I’m guessing they’d taken a wrong exit at the roundabout to the east, and Waze was looking to get them back on track.
The thing is, as the mapping of this junction currently stands I can’t see a way of preventing a U-turn instruction being issued which doesn’t bugger up the junction for other legal manoeuvres. That notwithstanding, there’s something about the way it’s mapped at the moment which seems a bit ‘off’, if you see what I mean, but I can’t quite put my finger on it!
The only thing which springs to mind is to turn this segment into two discrete segments - one for traffic coming from the west to turn right into Aldi, and another one for traffic from the east to turn right into Reeds Ln. - with turn restrictions set so as to prevent U-turn instructions being given. However, to my mind that would make the way it’s mapped even more clunky than it already looks. Anyone got any thoughts?
You’ve got a few choices;
- Leave as is and an L5 can map a Junction Box to control / restrict the u-turn
- Split the median segment to 2, but exit but Aldi into Reeds Ln doesn’t really need an instruction, it will get TR/TL
- Simplify the junction to the bare minimum and mis-align the segments, which risks another editor changing it all back again.
If you were to tweak the angle on the median segment to 90deg both top and bottom (at the moment its 72deg at the top), would that meet the criteria for u-turn prevention?
I don’t think it would, no - because restricting any turns from the median segment would prevent some perfectly legal right-turns out of Aldi or Reeds Ln.
Chris, which of your solutions would you suggest as being the most appropriate here? I think I’d probably have gone for the second one, but then there’s the superfluous turn instructions for an Aldi -> Reeds Ln journey, which I hadn’t considered, to deal with. Guidance would be appreciated.
Kevin is correct in that we should be able to trigger detour prevention as this is essentially a # junction, but the median segment is too long to comfortably map this, below image is the longest I could achieve and still trigger DP.
I think a JB would be best, any simplification or deliberate misalignment of the junction would require a map comment, a JB will actually lock the junction anyway.
Sounds like that’s the way forward. I guess I need to ask a L5 editor to jump in and take care of this one, then! 
Looks like there might be another segment required to allow traffic to turn right in/out of the riding stables?
See the ‘Keep Clear’ marking just East of the lights.
I’d agree, Andrew - good spot, I didn’t take that into consideration. I guess the junction box will need extending eastwards to encompass the additional segments here, so as to prevent U-turn instructions being given involving the new median segment here. I’m only L3 and the A553 is locked at L4, so I’ll either need the main road dropping to L3 so that I can add the necessary segments and then get an L5 to deal with the junction box ; or might just be easier to ask one of you lovely L5s to just do the whole thing!!