Train platforms are liminal spaces between people and machines. In this case, the train platform is next to a heavy freight line that MARC shares with the CSX railroad. You can be on the platform with a freight train rolling by and be within arm’s length of the cars. Not an unusual thing in itself, but not something most people experience when driving cars.
In the Washington, DC, area, most train tracks don’t cross roads. Rather, they run above or below the road so that trains and car traffic don’t interact. They are almost two different worlds. The sense of place you get riding the train is different from the one you get driving. What’s a few miles apart by one method might be quite ways apart by the other. In places like this, you get to cross over from one world into the other.