Federal regulators issued emergency rules Tuesday requiring extensive tests on crude oil moving by rail, concluding the system had become “an imminent hazard to public health and safety and the environment.” The order is aimed at operations in one of the U.S.’s booming oil fields, the Bakken Shale in North Dakota, where production has far outpaced the availability of pipelines to move crude to refineries. In just a few years, hundred-car trains full of Bakken oil have started moving through major North American cities—and been involved in several explosive accidents. The Transportation Department said the order is aimed at Bakken crude but will cover shipments from anywhere. While oil is classified as a hazardous material, it isn’t generally linked to explosions. But Bakken crude is more volatile than other oils and is more likely to emit flammable gases, as The Wall Street Journal reported earlier this week. The order […]