Very true, but surprisingly stupid can be on both sides. We were on interstate (In our motorhome towing a vehicle) and a truck was merging. We could not pull over as there was traffic passing, also in front and back of us - the trucker got 'really' mad at us, went very fast to get around us, then - get this - slammed on his breaks. Dh almost lost it - scared us to death.
I tried to get his license tag but he high tailed it, and we weren't going to be stupid and try to catch him. We don't mess with road rage - too may nut cases out there.