It's fascinating to me that you mention Pittsburgh lefts as a sign of altruism / global-outcome-optimization. I currently live in Pittsburgh and... let's just s

It's fascinating to me that you mention Pittsburgh lefts as a sign of altruism / global-outcome-optimization. I currently live in Pittsburgh and... let's just say that I would not hold the average driver up as a model of selflessness. I think it's more that we've reached a local equilibrium: new drivers learn quickly to wait when a light turns green, as a matter of avoiding accidents, and also to take advantage of that pause when turning left, as a matter of not angering everyone behind them. It's difficult to change the equilibrium as long as you interact with others following the current system. (It's entirely possible that one could view this as emergent-behavior-converging-on-altruism without anyone consciously being altruistic. I'm just saying that anecdotally, it doesn't seem to derive directly from conscious altruistic values.)