The notion of the crossroads as a sacred place is older than Robert Johnson, older than the blues, older than the automobile or the Romans who laid the first large-scale transportation network. The crossroads contains possibilities, changes, choices. It is where the gods live and the demons dwell. Soon, that may be almost literally true.
A recent Virginia Tech study suggests that the best way for driverless vehicles to handle intersections may be to hand over their decision trees to an “intersection controller” 200 meters or so before they actually reach said intersection. The “intersection controller” will possess local intelligence and will adjust the speed and behavior of incoming vehicles.
… the intersection controller governs the vehicles within 200 meters from the intersection. The vehicles report their physical characteristics, such as power, mass, speed, location, and acceleration.
“The aim of giving complete authority to the controller is to overcome any selfish behavior by an autonomous vehicle and benefit all vehicles in the intersection zone… The controller determines the optimum speed and acceleration at each time step for every vehicle within the intersection zone by processing the input data through a real-time simulator/tool.”
The system will begin testing at a Virginia Tech roundabout in the near future.
Speaking as someone who occasionally designs complex systems in his day job, I can’t decide if the potential for mayhem is made greater by allowing all the driverless cars to make their own wacky decisions or by turning over control to a system which could easily be compromised. If you have ten thousand cars going through an intersection every day, the chances are high that one of them will misbehave, but the others should be able to compensate. A malicious “intersection controller”, on the other hand, could just stack up dead bodies like cordwood until its registers overflowed.
It’s also a certainty that people will figure out how to game the intersection controller for their own benefit. One way would be to program your car to report brake failure 200 meters out. The intersection controller will cheerfully stop all other traffic for safety’s sake and you can just glide through like royalty. Some kid with a laptop can also sit under the intersection controller and generate phantom traffic. If all the traffic is encrypted, it can be recorded and replayed to cause havoc. Alternately, one could impersonate an intersection controller, pull a solid man-in-the-middle attack, and make pretty metal sculptures.
There’s something very touching about the way advocates of increased central control assume that everyone will just happily go along with whatever scheme they’ve dreamed up this week, whether it’s intersection controllers, mandatory smog inspections, or 85-mph speedometers to limit highway exuberance. There are more things in heaven and earth than are dreamt of their philosophy. The crossroads are a place of chaos as well as divinity. Ask Robert Johnson.