When it does happen, the majority (not all) of the drivers are either really drunk or high. Sometimes the signs aren't posted clearly or have been torn down. Other times, the drivers are too old and shouldn't be behind the wheel anymore. Then of course, you have your kamikaze drivers who are trying to commit suicide. That happened a couple of years back on a thruway near where I live. This idiot didn't manage to kill himself but he did kill a young couple and their unborn child. He is now in jail.