> They can use the streets proper if they want to.

How about no? They'll block traffic there, too.

Vehicles have been far too dominant in city planning, it's probably time to re-prioritize, make it look more like Netherlands or some other European countries perhaps.

I suggest a priority order somewhat like:

pedestrians > bicyclists > delivery bots > vehicles

currently in America I suppose it probably looks more like this currently:

vehicles > delivery bots > pedestrians.

Only at first, they'll fragment after the first few cars.