KET question

A very simple question. Maybe not..

Is there any clearly written/laid out in the KET rules from which side, right or left, can drive straight through the intersection? I mean when there are no signs on poles or scratched lines on the road, but the intersection can easily fit 2 cars in its lane.

I am attaching an example.

Exactly the same intersection and situation with the green car and that very nicely drawn yellow car.

When there are no arrows drawn either on the pole signs or on the road itself, only the main and side signs, who can drive and in which direction?

I always drive straight at such intersections from the left side (close to the separated lane), because both straight and left-turning cars have practically the same obstacles, that is, other cars on both sides. If everyone started driving straight from the right, it would hinder the passage of those who want to turn right, because when turning right, the obstacle is only on one side.

It would also be very interesting to know who would be at fault if both the green and yellow cars were going straight and collided.

VERY IMPORTANT: Please note that the road directly beyond the intersection no longer has two lanes, only one. And both yellow and green auto collide. Who is to blame?