> Normally, you just step off the road when a car comes. I suppose this doesn't work for high heels, but those can't handle storm drains either. You can even walk off the road.

This is assuming that the road something you can walk next to. And it's not amazing advice for roads with blind corners and such.

Sidewalks do actually help; drivers respond to their built environment, and most drivers do not want to scuff their cars by hitting the curb or other obstacles in the road.

The real crux of the problem is that the suburbs have become surrounded and cut across by massive high-speed traffic moats which are inherently unsafe for pedestrians because of the speed differential. Yet to walk in the suburbs you can't avoid these moats. And dissuading people from walking is near impossible, since the poor are now migrating to suburban areas and they are the ones least likely to have cars due to the cost.