These are little, under-achieving men with low self esteem that tailgate people and make loud hot rod sounds with their 8000 lb. noisemakers. They are usually wife beating drunks and have crappy jobs. The size of the truck in many instances is inversely proportional to the size of his "junk." It makes people like me laugh my ass off when they can't get their way in traffic.
"Man. Those angry truck men are really following us closely. Bruce, grab the gun."