Lower speed limits for railroads may be ineffective at keeping oil trains on the tracks and preventing massive fireballs, such as those triggered in a series of recent derailments, the chief U.S. railroad regulator said. “If you’re going to slow trains down, you’re going to have to slow them down to 12 miles an hour,” Sarah Feinberg, acting chief of the Federal Railroad Administration, told reporters in Washington Friday. “And then you would just have other dangers. People queuing up at grade crossings while train car after train car of volatile product goes by,” she said. “That’s not good either.” A surge in U.S. oil production has increased the amount of crude moved by rail 5,000 percent since 2009, much of it from North Dakota’s booming Bakken field. A corresponding jump in accidents, including a 2013 oil-train derailment and explosion that killed 47 people in Lac-Megantic, Quebec, […]