This animation shows how every Amtrak train in America is scheduled to move, over the course of one typical week.
Watching the animation run, it appears as though three separate systems run at the same time, almost independent of each other: The Northeast Corridor from Boston to Washington, the midwest's “Chicago hub,” and the west coast. Meanwhile, the south and interior west see trains few and far between.
The nationwide peak comes on Friday and Sunday evenings as people leave for weekend getaways and return home. At those times, over 130 trains are running at a single time. At the other end of the spectrum, around 40 are running at 2:30 in the morning.
What do you see that's interesting?