Lucas has pointed out Rule 1 concerning drivers (in St Louis, but I believe the heuristics can be generalized) and stop signs.

St Louis hosts more 4-way stop signs than any other locality, so I'm told by locals here, but you wouldn't know this to watch people drive. Instead of stopping and admiring a 4-way stop, most drivers roll right through, anxious I suppose to get a good view of the next 4-way stop sign down the pike.

Four-way stop signs are the invention of indecisive and too-eager-to-please minds, thinking that they can't figure out which way traffic predominantly flows, so they offend nobody by making everybody stop. What a waste of time and protocol.

Then there are the drivers in St Louis who stop at the stop sign, and stay stopped long past their protocol-sanctioned window to press on. They are "being nice" by playing traffic cop and waving some other driver through the intersection. One time I saw a driver fool two perpendicularly oriented drivers into both going ahead, resultilng in a satisfying low-impact crunch in the intersection.

Sometimes this well-intentioned but misdirected effort at generosity evolves into the "after you" game -- a kind of reverse "chicken' game where the first driver to move is the loser.

If only drivers could act like processors using the Ethernet, respecting protocol about who got to the intersection first, performing random, exponential back-off to break a tie. But then I guess a driver could get pulled over for exceeding the local bandwidth.