In the US side walk are already hilariously under designed and roads are already hilariously over designed. In many places side walks are barley large enough fo

In the US side walk are already hilariously under designed and roads are already hilariously over designed. In many places side walks are barley large enough for pedestrians and bikes to cross. And pedestrian infrastructure is just horrible designed for wheeled vehicles in the first place. As people with kid strollers and wheel chairs find out quickly. The actual solution, that pretty much every other first world country in the world has recognized is to start to build proper safe infrastructure for bikes (and the US overwhelmingly has plenty of space for that). Or to lower car traffic speed such that sharing can be done safely. If the US had huge sidewalks everywhere and fantastic design for access of wheeled vehicle, your suggestion might make sense, in the actual world, it doesn't, it just makes the world worse for people that walk and those that cycle. This is literally already all figured out and backed up with plenty of research but somehow people have to come up with their own 'solutions'.