Freight trains that haul an increasingly large amount of oil across the United States will have to improve safety mechanisms under new regulations proposed by the Obama administration Wednesday. The new rules include lower speed limits, new brake requirements, tougher regulations on the sturdiness of oil tank construction and a plan for phasing out some older oil tank cars. As a result of the rapid increase in oil production in North America in recent years, a growing volume of crude is being moved from well-head to refinery via freight trains—an increase of 423 percent between 2011 and 2012, according to the Department of Transportation.