> If pedestrians are getting hit by cars one of two things has happened: the pedestrian jaywalked or a driver didn't stop when required -- both cases which have nothing to do with lane width.

The driver will be able to stop when required when they're driving slower, which they certainly will do when the streets are designed to make them drive slower.

>if the problem is excessive speed, then traffic enforcement is the problem.

This is the solution that we've already tried for decades that doesn't work. When you make it more effective with solutions such as speed cameras, people decry it as a cash grab and they elect politicians that promise to remove them.