The Mexican Roundabout Problem

Autonomous vehicles are in the news, but I wonder what would happen if 4 autonomous cars arrived simultaneously at a roundabout from all 4 directions?

With human driven cars, one car (usually the BMW or Volvo) would make a slightly different risk assessment and slam the pedal to the metal, thereby gaining an advantage over the car to the right.

Autonomous cars, however, would adhere to the Highway Code and cause a traffic jam by sitting there in a considerate manner to allow the car on the right to proceed. A Mexican standoff.

Roundabouts may have to be replaced with signals giving sequenced priority. The only other solution would be for manufacturers to programme their vehicles according to stereotypes of their usual clientele - BMW and Volvo autonomous cars would be controlled by an AI wanker chip that behaves in an inconsiderate manner at every opportunity.