I look forward to a time when vehicles and pedestrians aren't interacting at all. Vehicles should be below where people walk and ride bikes. Either roads are designed to be underground or we one layer up from existing roads. And that's were storefronts will be.
Robotic construction is going to drive down construction costs dramatically, so I think it will be feasible. Vehicles will be totally electric a few decades from now, so pollution will be less of an issue. Cities will get quieter and we'll see a lot more vegetable gardens and open space where streets used to be.
I remember parts of Hong Kong being designed like this when I visited 10 years ago. It felt a little awkward but I could see this working nicely. Ideally we'd just remove the need for cars altogether though. Maybe freight could come in underground.
Robotic construction is going to drive down construction costs dramatically, so I think it will be feasible. Vehicles will be totally electric a few decades from now, so pollution will be less of an issue. Cities will get quieter and we'll see a lot more vegetable gardens and open space where streets used to be.