T shirt with a big arrow and words like this:
<-------
KEEP LEFT
Actually I sometimes wonder about the idiots drivers too.
I have been out on quiet Sunday mornings, doing a nice bike ride down the 6 lane boulevard... 3 lanes either way and I am in one... and taking the whole lane (what the heck no one else around...) and lo and behold the ONE motorist that does come along, gets all bent out of shape and honks at me. TWO, not one, but TWO empty lanes to the left that the idiot motorist could use, and noooo, they chose my lane, and then honk at me.
Guess I should have moved over to the left and given the idiot the far right lane....
He was obviously "slow." (in the head)