The PATCO Speedline looks very possible to make. It has 13 Stations and is 14,2 miles (22,86 km) long. Unfortunately, this route seems to use some form of ATO. But it can be turned off to operate the train manually. This route runs between Philadelphia Pennsylvania, and Camden County, New Jersey. It's sort of like a Subway and to be frank, I would be the first one to buy it. Here's a video of the PATCO Speedline in action:
