>in many parts of the world where there are no traffic lights or stop signs, people get on just fine
Well, sort of. Road injuries / fatalities in countries without these kinds of regulations are about an 3-4x higher than in those that do have them.
https://www.who.int/publications/i/item/9789241565684
Number of traffic accidents went down by 50% in this town.
https://worksthatwork.com/1/shared-space
Number of traffic accidents went down by 50% in this town.
https://worksthatwork.com/1/shared-space