Here's an idea: if we're really aimed toward education, let's start writing to our local newspapers. I'm not just talking about letters to the editor--most local newspapers have a sort of guest-editorial feature, where you can write a somewhat longer piece than a letter--a kind of citizen's editorial. They're not terribly long--usually 300-600 words--that's around 2 typed, double-spaced pages, but they give you more space than a letter, and they're usually featured more prominently than the letters. You could write about the dangers of all the things being discussed in this thread, or any other dangerous thing you've seen motorists do around cyclists.

Now admittedly, for this to do any good, people have to read it, and a certain percentage of the likely offenders are probably not newspaper readers anyway, but a lot of them are, and in the case of teens, maybe their parents are. And it doesn't cost you anything more than a couple of hours of ranting on paper.

Let us know if you intend to try it and whether it gets printed or not. If your local paper is quite small, it can be surprisingly easy to get this kind of writing printed. Good luck!