oh, mike, don't get me started.. my road-road rage is even worse than my runner's road rage.
how about people who try to merge onto major interstates, like I-95, going 40 miles per hour.
or people who see a cop at the bottom (top?) of the on ramp and so they slam on their breaks, slowing down to 20 or so mph, causing all traffic trying to merge AT THE SPEED LIMIT to slam on their breaks and swerve to avoid a huge pile-up.
or people who, despite beign able to CLEARLY see that there is NO ONE behind your car, insist on pulling out in front of you and almost causing deadly accidents.
and my favorite, which i have actually witnessed, people who realize they've gotten off at the wrong exit and, as if they've never gotten off a highway before and don't know that the on ramp for EITHER DIRECTION can be found shortly after the bottom of the off-ramp, TRY TO BACK UP THE RAMP TO RETURN TO THE HIGHWAY.
omg, the idiots. 
insanity without ambition is like a machine gun without bullets.