Worse than that is the fact that people that drive like them are creating traffic for them. If everyone stayed in the lane, and went with the flow of traffic, traffic jams would be less common, especially on highways.

There's a supply chain theory known as the bullwhip effect, but it absolutely applies to traffic patterns also. It says that a small slowdown in one point flows through every point down the line from it, growing at each.

If I have to hit my breaks because some ass is driving like hes in an action movie, the person behind me has to slow down slightly more because there's a lag time between me letting off my breaks and them doing so. In traffic, that lag time grows with every car in the line.