[pixl97]

>So the question is does the rate of derailments scale with the number of individual cars or with the number of trains?

You have to take in a much larger number of factors than that.

The railroad industry is currently pushing their new just in time paradigm which has been leading to attempted strikes in the US (Uncle Joe says no) by the railroad workers. The railroad operators are pushing for longer trains, less engineers per train, and less inspection time per car while also playing computerized shipping optimizations that put the number of 'hazards' on a train just below the regulated minimum number of cars so they don't have to declare it.

It's just ironic that this incident that got national news happened so quickly after the railroad co's got their no right to strike validated. It looks like it could very well be their undoing.