western europe – A little problem in European traffic rules: Priority of a car sitting on a “stepstone” island

Here is an intersection which always gives me trouble:

Image of an intersection

  • The usual continental European traffic rules apply;
  • There are two lanes which have right-of-way, one going towards the North-West, and one towards the South-East ;
  • There is a side-road coming in from the East (is a highway off-ramp, actually) and a side-road going to the West (a highway on-ramp)
  • In the picture, the light blue area cannot be used as it is a bus lane, but that is not important here.

If you have a car A driving along the red path, it may encounter heavy traffic on both NW and SE lanes. There is a little “stepstone island” in between the lanes so that you can proceed across the NW lane if it is free, then wait for the SE lane to clear.

While car A is waiting on the “stepstone”, a car B initially on the NW lane may wish to turn to its left in order to proceed West, then also wait for the SE lane to clear.

Once the SE lane is clear, you have to decide which of A and B goes first. I am of the impression that it should be B as B is coming off the lan which has right-of-way but apparently opinions on this diverge, leading to hesitancy.

Is there an applicable rule to decide who goes first without having to resort to casting dice?