Driving slow in the left lane, driving slow in the center or right lane next to the person driving slow in the left lane, cutting people off, young people in Suzuki street bikes weaving between cars at 160+ mph, people who think that turn signals are a license to cut other drivers off, people who drive too closely to your rear end, people who drive with their high beams on and refuse to change to low beams even after you signal them to, people who rubberneck at minor accidents, people who run stop signs and red lights just because they feel like it, etc., etc.