Hundreds of thousands of tank cars full of crude oil snake across the nation each year, and the number is only increasing — in the last five years, it’s jumped 14-fold. Along with that, there’s been an increased number of accidents, derailments and spills. Public safety advocates are clamoring for more information about where the trains are going and how much crude they’re carrying, but it’s been almost impossible to come by. Regulators don’t collect it and the railroads have refused to disclose it. Why the secrecy?