My impression the past few years is that trains are being packed with coal.
It’s not merely coal, of course; there are other goods being shipped by rail. Furthermore, not all that coal is going to China. There are power plants near Washington, D.C., for example, that burn coal, although with much cleaner technology than the cost-sensitive Chinese use.
A highly efficient rail network carrying freight through the U.S. is good for the country’s economy in that it lowers shipping costs, especially with high fuel prices.