Ok picture this:
Roundabout exits onto a main road with two lanes. Two lanes continue for about three quarters of a mile then merge into one.
Left hand lane had a queue all the way up to maybe 100m from the roundabout, so I went down the right lane.
As I got to the front of the empty lane, I waited patiently to be let in and a man wound his window down and told me I should wait my turn (and also called me a fat bastard but that's not what the post is about, we can all agree that's a dick thing to say)
I thought that was the point of merge lanes - to stop one lane having a massive tailback and it's not like I pushed in, I was waiting for a gap!
Otherwise what's the point of two lanes...?
So was I BU?! What do you do?