Perception of speed

Ennie and I took a walk today after work and dinner. Right outside the apartment is a set of train tracks. The trains keep us up at night sometime, especially when a loud one goes by. Did I mention they're right outside the window? Perhaps 120 yards or so.But that's not the point.We were walking back to the apartment on the opposite side of the tracks when a train was passing by. Just a heavily laden freight train. We dutifully waited by the crossing gate as the train glided past.As the last car went by I looked both way and started to cross.Apparently this caused a stir.Why? I'm not quite sure. I had a good half-mile sight range (probably more actually) and nothing was coming from either direction.En pointed out that the Sound Transit train is pretty fast.Let's assume 60 mph. It doesn't go that fast, but it makes the math easy. I would have half a minute to cross the tracks before a train going 60 would cover half a mile. Suddenly it seems like an eternity.I think the human brain doesn't work that way. After evolving for millennia at nothing more than a running pace, things that go faster by a lot, or higher or whatever. Without having a mental model of what's going on it's hard to react in the correct way.