On the east coast of the United States, cities are merging. Their outskirts are growing together to form a megalopolis - a supercity. This was certainly an idea that Stefan and Dave were aware of, but also one to which they had never given too much thought.

That all changed one day in Brooklyn. Stefan was in town for the weekend, and had promised to stop by and see a friend who was in the Bronx. The subway didn't run far enough, so Dave pulled up a metro north map, and they noticed that the trains ran all the way into Connecticut.

This left us wondering, was that really the end of the line?

The search was on, and we spent the afternoon seeking out connections between the different rail systems. In the weeks to follow, busses, subways, ferries, streetcars, and commuter rail would be pieced together, until we had found a way to ride the entirety of the megalopolis on local public transit.

Last May we started in Fredericksburg, Virginia and using only local public transit - no cars, taxis, planes, or long-distance bus or rail services - we traveled to Portland, Maine.