Honestly, all shitty drivers. I once was in a 2 lane, and was going over a bridge over a highway, I was in the left, someone was behind me, and the entrance to get on the highway was just starting on my left, the guy decides to go right, around me, cut me off, then go into the lane of the high way. If I weren't in my work vehicle, I would've done some road rage shit. Also I was on another bridge (must be bad luck) but this time over the river, I was in the left lane (again bad luck) and there was a small gap between me and another car. A guy in the right lane decides to get over with a turn signal at last minute. If I dodnt brake hard, I would have hit them. So u flipped them off, they waved and I flipped them off again. Later on they called my boss telling them that lol. It was awesome