The nation’s railroads are asking safety regulators to require that all existing tank cars that carry crude oil, ethanol and other flammable liquids be modified or upgraded to better withstand accidents or be “aggressively” phased out of service. They are stopping short of recommending a deadline for the changes to the U.S. tank-car fleet or estimating the cost of the retrofits, which would be needed on 78,000 older tank cars and modifications to some of the 14,000 newer cars that don’t already comply with its suggested changes. The groups said they would leave those deadline and cost details to the Pipeline Hazardous Materials and Safety Administration, the federal agency responsible for regulating tank-car safety, which is beginning to craft new rules on tank cars. Trade groups representing the railroads—the Association of American Railroads and the American Short Line and Regional Railroad Association—plan to make their request Thursday. Two troubling […]