[dacracot]

The math is simple. This did not require a mathematician, just an cost benefit analysis.

($ * toilet each car) < shunting{($ * action * yard) + ($ * training * employee)} + ($ * accident cleanup) + ($ * customer bad will)

[ufo]

Read until the end again. The solution they came up with still only put toilets in 50% of the cars.

[dacracot]

And from a system perspective, I would wager that the cost is still higher given the complexity of their final solution.