Exactly. This is an actual issue in robotics/AI - "best" in each scenario might in turn become "worse" overall.

A funny story I read about once:

> I've got a good story about the mines using this tech. A mate works for them and was telling me after changing over to driverless trucks they started getting huge divots in the ramps in the mines.

> They went to site and watched the trucks to see what was going on, and the trucks were (with centimetre precision) changing gears in the exact same spot causing huge divots in the ground. They ended up having to program in a random number generator in that algorithm to avoid them.

Source: https://www.reddit.com/r/Futurology/comments/3p7qg6/driverle...

> Will the cars drive so passive/defensive that none of them have the "balls" to break symmetry?

Yes, that "behavior" had to be programmed in.

The autonomous vehicles had to learn to be "assertive" (ie. start rolling slowly into the intersection) in order to not confuse other drivers at the stop.

The vehicles also had to learn that a hipster standing on a fixie's pedals rocking back-and-forth was not an intersection hazard in spite of scoring high on the idiot detector.

I think the typical CS solution to such a deadlock would be a random exponential backoff, no?

The cars could easily have some sort of universal function to figure this out. Off the top of my head: The northmost car could go first, and if two cars are both "equally equally north" then the eastmost car could go.

Human drivers communicate in such a rare situation, e.g. by blinking lights to signal they won't go. Driverless cars should be able to do that as well.