It's interesting to watch this video of San Francisco's Market street from 1906: https://www.youtube.com/watch?v=8Q5Nur642BU https://www.youtube.com/watch?v=8Q

It's interesting to watch this video of San Francisco's Market street from 1906: https://www.youtube.com/watch?v=8Q5Nur642BU https://www.youtube.com/watch?v=8Q5Nur642BU Cars travel at walking pace, and cars, streetcars, horses, etc all coexist -- pedestrians seem to cross the street at will, not following any signals or staying in crosswalks. I think the reason this chaotic system works (aside from the lower speeds) is because street users expect the chaos, no one relies on a traffic signal to tell them when it's safe to cross, they know that they have to pay attention or they'll be run over (or will run over someone else).