Connectivity-relations for turn-directions?

Hey guys, one question for the experts:

Germany has signs that indicate that a priority road makes a turn:

This shows that the priority road makes a left turn, but also that you have to signal left to show that you’re staying on the road. A router would definitely be expected to tell you to “make a left”, because of this sign. So far so good, but sometimes, all the signs on a crossing aren’t really cohesive, and it can happen that the signs on each street of the crossing differ in a way you wouldn’t expect. Example:

Bird’s view:

Coming from the east (red arrow)

As you can see, if you come from the west, or north-west, and want to go east, (green arrows) you have to signal left, but if you come from the east and want to go west (red arrows), you must not signal at all.

I tried several times to solve this with geometry, but it always ends in a mess of oneway roads which don’t reflect the reality on ground.

Question: Are connectivity-relations made to solve these issues? I’m suspecting so, because this relation is listed in the proposal as an example to »mark what the “through” part of the oneway road actually means«. Since the relation doesn’t have “through” anywhere, I’m suspecting, that the general idea is that if you link from a lane on road A to a lane on road B and the lane on road A is a turn-lane with “left”, then this could be used by routers to create a “make a left turn” direction.

Is this assumption correct? If not: are there any other tags that I could use to give these turn-hints?

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