Good point. Sometimes on rare occasion I find a rail composition with distracting elements on the periphery (like parked cars with shiny chrome, high tension power lines, a billboard, etc.) and if I have a tripod, I can perfectly set the scene and trigger the shutter as the train passes through. Without the tripod, I can't hold everything as I want. But, normally I shoot handheld.
It is interesting that rail cars have become a canvas for artists. Back 40 years ago one hardly ever saw a painted car. The times have changed.