I use that middle lane to go down Broughton St too. Led to me being beeped by a bus because I was at the front of the lane and not moving because the queue for the Broughton St lights was backed up to the roundabout and it's a box junction. The bus was behind me and obviously wanted me out of the way.
I turned round and gave him a big shrug of the shoulders, pointing at the queue and the box junction markings, but with a wave of the hand busdriverman seemed to suggest I should just jump the queue.
As it was, the lights changed and a taxidriverman who was on the roundabout and observing the box junction waved me through ahead of him.
I'm pretty sure I was in the right and that busdriverdude should probably have been in the right hand lane if he wanted to go down Leith Walk, but I guess that would involve changing lanes straight after the bus stops at John Lewis?