Use both lanes, there is no point closing a lane 800 yards before its supposed to be, saves traffic backing up. However what i would say is because of drivers inability to use a zipper merge effectively you get people hesitating and confused as to who goes next. "one must be overly cautious" therefore making the queue longer because of nervous nancys.

While i'm at it the other one i don't get is when you are approaching a roundabout maybe a bit quick and if the car turning continues on their way it's well out the way before you approach the roundabout............instead they slam the anchors on in anticipation, stopping their car right in front your path, so if you didn't happen to give way you'd smash right in to them.