Cheap natural gas has slashed coal traffic across the U.S. rail network and in turn hit demand for diesel, demonstrating the interlocking relationship between the country’s energy and transport systems. U.S. rail freight declined more than 6 percent in the first 12 weeks of 2016 compared with a year earlier, according to the Association of American Railroads (AAR). Most categories of bulk freight were down compared with 2015 but by far the largest drop occurred in coal, the single-largest commodity hauled on the network. The number of railcars loaded with coal in the first 12 weeks was down by 32 percent compared with 2015 (“AAR reports weekly rail traffic for the week ending March 26”). Coal loadings are down because power plants have switched to burning inexpensive natural gas, […]