People who can't pick one goddamned lane and just continuously shift between all the lanes trying to find the "Perfect" lane. PROTIP: If you're not able to break through the traffic and get up to your preferred speed in the far left lane and there's just as much traffic in the next two lanes, it's not going to work out for you.
... Unless you're an automotive ninja, of course. In which case you'd be on two wheels instead.
... Unless you're an automotive ninja, of course. In which case you'd be on two wheels instead.