It could be that they are potheads but most of the time I think they are just obnoxious assholes who don't give a crap. I used to fdo a lot of bicycle riding around here and I remember how arrogant and nasty some of these drivers were. I had an old guy and his elderly wife nearly kill me once then he gave me a dirty look and the finger. I had the right of the way and they didn't care. Their attitude was, you are on a bike and you have no right to be there and I don;t have to yield to you. The attitude of a lot of these people is, "my car is bigger, heavier and stronger than your bike and I'll run you off the road". I don;t think they are on pot or drugs. They are just plain ol' nasty arrogant people. Of course , if you can get the law to search them for drugs then all the better. Serves them right for being pricks.