There is one safety feature that would universally make cars safer and not require radar or computers. Just simple speed governors based on geo-fencing and radio speed limit signs. It would be trivially easy to install on existing vehicles and much less expensive on new vehicles. In addition it would increase pedestrian safety by leaps and bounds. We do it for electric bicycles and scooters. Why not cars?
Aren't all the scooters just a flat 20/25 mph cap with no dynamic changing? I think drones are the things you're looking for where they avoid flying near airfields.