A junction area is needed here so you aren’t navigated onto a u-turn.
It’s not very common to add a junction box, but it might be perfectly correct. Formally, there’s probably no prohibition against turning back onto the on-ramp. In the similar cases I quickly looked at, there is no junction box. An alternative could be to place the off-ramp and on-ramp at the same node and set a red turn arrow from the off-ramp to the on-ramp, like here.
You haven’t seen how they do it in Denmark. They love them as if they were beer. Roundabouts become intersection areas and then anything goes anyway. I don’t agree with everything, but I’ve seen something similar to our case where they had one.
Maybe we should start a new tradition and not be so stingy? The visual effect of there being two separate roads is important — and extra important so people don’t drive down the wrong side of the motorway. After all, trucks can end up in nature reserves on narrow bridges, and this is even more sensitive.
It may not be a prohibited move, but if you do it, you’ll end up in the grass or driving in the wrong lane to get around. With a truck, it’s a no-go and dangerous.
Is this really a problem? I haven’t heard of being able to get a route off onto a curved ramp and then a short stretch on a road with a low road class and then back onto the highway via the on-ramp.
On the other hand, you get that problem on regular ramps that run parallel to the highway, and we normally block that shortcut there, e.g., here: https://waze.com/sv/editor?env=row&lat=59.18883&lon=17.45854&marker=true&zoomLevel=17&segments=415200175
Just the fact that part of the path goes over a segment with a lower road class means it’s not included in the route calculation.
/Ulle
It’s only a problem when there’s a traffic jam on the highway. Then it calculates routes like crazy. Plus, when it suggests an alternative route that you then choose and it doesn’t quite keep up, it sends you back to the highway.
OK, it doesn’t hurt, so I’ve added a JB at the southern intersection. At the northern one, I’ve instead redesigned the intersection so the problem can be solved with turn arrows.
The latter is probably a simpler solution but doesn’t work if the distance between the ramp segments is too large, as the visualization then becomes poor.
However, neither case prevents Waze from routing away from the ramp and turning around at a suitable spot to then return to the on-ramp.
/Ulle