I think it has something to do with a superiority complex or even mental defect with drivers who ride up another's ***. I do driver training as part of my work and have some interest asking the group if they tailgate and then ask why. Some will say because the driver ahead is a slowpoke then I say what if the driver is already going over the speed limit? Then I ask does it piss ya off when someone tailgates you? Often the obvious reply is yes. Then we get into how this causes many accidents and multi-vehicle crashes. I wrap with...if one tailgates another, that person is totally at the mercy of the driver in front as they see what's ahead...could be another car or bike ahead, a rock, debris, pothole, animal, or even a kid. The daughter of a family friend was killed when the driver behind her swerved to go around her as she was making a turn...driver behind that guy didn't see her in time to avoid rear-ending her at 50 MPH. Her neck was broken...she was all of 19 years old.