From Laura Michet's blog, a post about an abandoned project to catalog Los Angeles' "No Pedestrian Crossing" signs:

The main thing I'd want to communicate is that the places where these signs go up are uniformly miserable. It sucks to be a person on foot in a place where the state has to warn you that it's too dangerous to cross a regular city street. These streets are terrible, loud, dirty, and they smell bad. A crowded urban street with a "no pedestrian crossing" sign is a place created by infrastructural and institutional failure and it sucks that we have any of them in these busy neighborhoods.

I have never seen a sign trying to ward off pedestrians from crossing the street in São Paulo—not exactly the shining beacon of pedestrian infrastructure. There are rights of way in the city that you can't really cross as a pedestrian, but those are on the "road" side of the street/road divide—things like the Marginal Pinheiros, where there's nothing to cross to anyway; or expressways that are grade-separated. Those often have walkways, and if you wanted to cross them on foot you'd have to jump a median concrete barrier. The idea of a regular ass street with regular ass sidewalk and a sign that goes "no, fuck you" to pedestrian crossings is nuts.