Recently I had a semi driver who was unhappy with my lawful cruising speed. First he flashed his high beams (daytime); then he left 'em on. Then he laid on the horn for about 30 seconds. Oh- you want to go even slower? That can be arranged- and it was. Then he pulled over- why I don't know- and the convoy behind him passed him up while I continued merrily on my way. The highway we were on was- with the exception of a few rural intersections and curves- all passing zone.
It's not my fault people overpopulated the area such that safe passing is often not possible anymore.
