Originally Posted by woodcraft

I disagree with the thought that there is no effect without rigorous enforcement.

It takes a while for behaviors to change, but over time, they do.

Maybe you used to throw trash out the car window, & now you don't, but probably never got a citation.

In my (norcal) area, I think it's partly a numbers thing- you could angrily buzz the few cyclists, but now there's too many.