The absolutly worst thing I know when I venture out on the Dutch roads is [stag]tailgating[/stag]. First I drive a [stag]motorbike[/stag], and if you don't know it - these things can both out [stag]accelerate[/stag] almost anything, and on a strait out break anything (that is if you're not driving a car which cost more that most houses).
So if I'm driving at 120km/h and have a car 5 - 10 meters behind me I get nervous, as I know that if I break hard there is a chance that I'll end up in the hospital.
The other week I was told that in some US states you are at fault if you hit someone from behind, no matter what the reason was (well there might be reason why you would not be). I think that we would see less accidents caused by tailgating if that would be the law in this wonderfull flat country.