To a pretty good approximation, everything that feasibly can get shipped by rail already is. Railroad companies operate fairly close to capacity, and they have no desire to reduce their massive profit margins building new rails en masse and handling the maintenance burden. That leaves only the shippers themselves, who are often much smaller companies that couldn't reasonably build a new rail line or buy cars for every customer, but can easily afford a few trucks to be relocated anywhere in the country they have demand.
> Railroad companies operate fairly close to capacity, and they have no desire to reduce their massive profit margins building new rails en masse and handling the maintenance burden.
I'm talking from a "looking at the wide, societal picture" viewpoint. And from that, it makes so much more sense to shift as much long haul traffic to railways as possible. I'm aware that the mechanics of modern day capitalism are not aligned with what's best for society at large, long-term - mostly that railway infrastructure is orders of magnitude better regarding emissions and energy consumptions, but that it takes many more years for investments to pay off, which is why there is so few railway capacity in the US and what is there, is often enough in shabby condition.
