The worst is truckers who decide they want to pass another 18 wheeler and change lanes when you are coming up on them fast. You have to slow way down while they take 10 miles to pass the truck to the left of them that's only moving 2-3 mph slower than them. You end up going 55-60 mph hour stuck behind some dumbass that is essentially killing both lanes of traffic.
In fact, anybody that changes into the fast lane without gauging the speed of upcoming traffic is a D-bag. Just wait the 30 seconds until I pass you before jumping into the fast lane.
This this this! Particularly when there are only 2 lanes.