>You could imagine a world in which streets were pedestrianized and where we planted trees and gardens and in what is currently space reserved for parking, and closed streets, outside schools, so kids can have places to play.

I would love to see a LOT more of this in urban centers.

I live in a college town that is about the same size as Iowa City. Iowa City has taken the step of closing off their downtown and making it mostly pedestrian space. It's incredibly nice to explore the area on foot. Our city has considered the same idea but pedestrianizing our downtown has been so controversial when it has been discussed, it hasn't come up for over a decade- mayors are scared to death to touch it.

Part of the reason is poor past civic planning would make it very expensive to correct. The main conduit through the downtown business district is also the major East-West artery of town, making the street one of those dreaded "stroads-" a street in the sense that there is heavy commercial and residential presence, resulting in a LOT of local foot traffic and stops all day long; mixed with traffic that just wants to get through downtown to somewhere else. So half of the traffic is looking for parking and the other half is running red lights to get somewhere else as fast as possible.

There have been, predictably, many incidents involving cars, pedestrians and bicycles. But not one inch moved on what's become the 800lb gorilla. I don't think a solution is even possible.