This happened to me about 1.5 weeks ago was on Lincoln Road during the morning rush. Was in the right lane to get on SH16 towards the city. The van which was ahead of me suddenly changed lane to the left which I thought a little weird since they'd been ahead of me for a while. (The left lane used by those who want to head west on SH16 or who want to get on Triangle Road was a freer flowing as it often is. I think it would actually be even freer if not for muppets trying to force their way into the right lane to get on the motorway heading towards the city near the end.)
Probably because I don't drive much especially at peak time, was a while before it occurred to me what they were going to do. Sure enough they pushed back into the right hand lane at the Lincoln Road/Universal Road traffic lights. They only got 2 cars or so ahead (we weren't that far from the lights) but peeved me off no end. I give them credit for doing it there rather than further ahead but still.....
Was actually enough that I considered writing about them but I couldn't make out the number plate once it occurred to me what was going to happen. Technically I'm not sure if there's any clear violation in the normal case since it's really just a two lane road for most of it. Although I believe in the case I mentioned, they did block the junction temporarily as you'd expect. I also wonder whether it would fall under something like inconsiderate driving if it could be proven you did it intentionally. But intentional is the problem. Even when they change lane then change back, they could simply say I was considering going to X, but changed my mind again. But in any case, it was some sort of marked company van so depending on the boss (assuming it wasn't the boss) they might have their own views if they received a complaint regardless of the legal situation.
Like kryptonjon lane pushers are one of my pet peeve. Kiwi drivers at least aren't as bad as Malaysians. If you've just turned into the road coming from somewhere else or made a genuine mistake I'm happy to let you in. But not when you intentionally drove on the free flowing lane knowing full well you're going to have to force yourself into the slower lane ahead and where you weren't bypassing any bottlenecks. It also sucks when you're in the freer flowing lane and it's hindered because some idiot is trying to force their way.
I suspect it probably causes a fair few minor accidents too. Both people trying to force their way in and when someone doesn't want to let them. And also because it's means a lot of people try to follow the next car very closely to try and stop cars forcing their way in.