when a motorway or A road narrows from 3 to 2 lanes and every one filters into the lanes without needing to brake, then some imbecile speeds down the lane and right where it disappears, jams themselves in right at the front causing everyone to brake.
Some clever clogs will surely be along to inform me that this is what you're meant to do - I DONT CARE
Another thing that annoys me is when people pull out of a side road too close to you, then don't bother to accelerate. Fine, you misjudged that distance but don't make me come to a complete stop.
They make very little difference to my journeys in reality but it's the selfishness that other people assume that people should wait for them which annoys me.