Bit of background-
The road used to go straight on, with a left turn junction. A supermarket was built and they turned the junction into a roundabout, adding another left turn for the store entrance. So there is now a roundabout with 3 exits: exit 1 is store, exit 2 is old left turn, exit 3 is old straight on. We need to turn down exit 2 for home.
The problem is the lane markings. On the approach to the roundabout there is 2 lanes. Left lane is marked with a left arrow and 'store'. The right hand lane is marked with a straight arrow and the road number of exit 3. Neither lane directs you to exit 2 at all- so it's a bit of a free for all with people going down exit 2 from either lane, and some near misses resulting.
One of us uses the left lane for exit 2, saying that as it is unclear you should default to the left lane. In the event of an accident, it would be the right lane driver's fault for not checking their mirrors and indicating before pulling off.
One of us uses the right lane for exit 2, saying that left lane is clearly marked only for the store exit, and in the event of an accident it would be the left lane driver's fault for taking the 2nd exit in a left turn only lane.
Which is more correct?