The University of Minnesota Center for Transportation Studies Intelligent Transportation Systems Institute has produced a handy little flash game where you can experience the life of a traffic planner in a series of increasingly complicated traffic challenges.
The game begins in the Stalinian Central Bureau of Traffic Control, where a wrinkly old man pulls you out of your job at the mail room to come save the traffic control system. You are brought to a space command-like control room and put to work setting traffic lights to stop and go. Meanwhile frustrated drivers stuck in the gridlock you create blare their car horns to get your attention, and if their "frustration level" rises too high you fail out of the level. As the road network gets as complicated as four intersections on a square grid, the traffic becomes completely overwhelming and failure is inevitable, but the old man reassures you that they too have failed anyway.
It's hard to tell where the joke begins and where it ends with this app. According to the ITS news feed the game's purpose is to let "high school students try their hand at working in the engineering and transportation field." And, as if astonished by their own profession's ridicule, the game's description of the traffic control room reads "the traffic control center in the game is realistic: many large metropolitan areas (such as New York, Boston, and the Twin Cities) have traffic control centers that actually do look like that."
You must play it and experience it for yourself.
Why was this made? Are traffic engineers passively crying out for someone to put them out of their misery? Traffic, after all, is the most complex pattern of all those that compose a city. While buildings move around over the span of years, traffic consists of thousands to millions of randomly moving parts in the span of a day. Despite all the efforts that have been invested in designing traffic control devices, the "frustration level" for drivers has only risen.
Some traffic engineers have learned that the problem was not traffic but central planning, the foremost of which was Hans Monderman. By running a driving school and studying how people related to their environment, Monderman discovered that the traffic control devices the profession employed were not only useless but counter-productive. He set out to remove traffic control and empower drivers to control themselves and make decisions based on their context. His model for traffic control is to design the context so that drivers will control themselves and each other, a scheme called shared space.
The basis of an emergent intelligent system is that individuals act and make choices based on a shared system of contextual rules. This decentralizes decision making and makes possible the optimal adaptation to chaotic environments. We can see this in the superior performance of the roundabout as compared to the traffic light for traffic flow. A roundabout is a rule that tells drivers to yield to other drivers coming from other directions. It is decentralized. A traffic light simply tells drivers when to stop and go, whatever the situation may be at the current time. When the traffic light status becomes completely alienated from reality, gridlock occurs and frustration boils. What frustrates drivers is their powerlessness to contribute to the intelligence of the system, and the utter waste of time being imposed on them because of traffic planners unfamiliar with the precise circumstances taking place.
It should be no wonder then that when the traffic control system fails, traffic flows better.
The Intelligent Transportation Systems Institutes of this world are trying to create intelligent traffic control tools, but those are another form of fake complexity. When all drivers, cyclists and pedestrians are optimizing their behavior based on simple traffic rules, that is when traffic becomes intelligent.