I mean, I've seen the pictures... Just not in the wild. One of those things that seems like a nice idea, but good luck ever getting anyone to pay for such en mass. Have you seen any of these around Tampa Bay? I've never seen anything except the unprotected margins, excepting trails which are not sharing infrastructure with roads.
When someone actually takes the little money to build one, there is an army of people essentially saying they'd rather have 5 more parking spots than safe infrastructure. Then when somebody is hit, like here, the same people argue you can't blame the driver because look how bad the infrastructure is. You can see it in this very thread with people arguing bikes should fuck off to the sidewalk.
