As I took the bus to a friend’s campus yesterday, I wondered just how many people use public transport on any given day. The number was incomprehensible to me. The public transportation system of the world seems to be a phenomenon in and of itself. Millions of people move through it with rush hours being the peak, the whole system pulsing with human activity. Things in this phenomenon would be people, buses, trains, taxis, and subway cars. Frameworks would be routes and train tracks, such as the image of the London Tube Route Map, even city streets are part of this framework. And clockworks in this system would be rush hours, schedules, and the ebb and flow of humanity to and from their jobs, homes, and every other place transportation takes them. This ebb and flow is ultimately what makes up most of the phenomenon. The global transit system has no distinct beginning, but it does have traceable origins, all the way from the invention of the wheel. The transit system has boundary conditions and limitations. It has duration, hierarchies, and sub-systems. It exhibits change and can also be modeled in terms of usage, and routing. As far as behavior goes, it is hard to define, but I do believe that is has a sense of internal behavior, pulsing and moving all over the world.