For many cars and ares in the world the turning radius usable on small streets is not really a problem.
> open up additional safety buffer space
I don't think that matters, we already have very save cross road designs, we just need to use them.
I’m not sure that this does anything for pedestrian safety, though.
E.g. if you are on a bike you can have a hyper small turning radius, but only if you mover very very slow (but not too slow ;) ).
The problem is requiring such a radius would be a safety hazard, as people would all the time not get the turn due to driving to fast, even if they literally started driving a moment ago due to a red traffic light.
Spherical wheels can do it more efficiently because they can do it with less slippage. But regular wheels can absolutely do that maneuver. Even tracks can. Heavy equipment does this all the time.
Spherical wheels provide zero radius for off-original-orientation movement from a stop (and similar but somewhat less benefit at low speed) because you can thrust independently of the direction of orientation.
This isn't the same a reduced turning radius, but it has similar effects for certain low speed maneuvers to an extreme reduction in turning radius.
The only thing you can get from spherical wheels that you can’t get from standard wheels with comparable drive is sideways motion, which granted, would be kind of awesome (zooming down the highway and switching lanes with no directional change), but also not actually that useful. You can also get a bit of this from independently-steerable wheels, as someone else pointed out. But that won’t get you sideways motion from a standstill if that’s somehow useful.
You can actually get it from independently steerable wheels with AWD if they are mounted and driven independently (practical with an electric power system) rather than off a common axle; I’m pretty sure I recall concept vehicles (or at least designs) from various car companies with that design, for that purpose.
The typical highlighted urban use case is zero-approach parallel parking. For autonomous vehicles, especially, it would make higher density but basically random access (and, therefore, not subject to easy blockage by small number of vehicle failures) storage possible
> zooming down the highway and switching lanes with no directional change
You probably can't get better than AWD with independently steerable wheels on an axle for this, because the limiting factor in how far you can change thrust direction while maintaining control at highway speed is going to be traction long before it is maximum wheel angle.