- Associated Press - Thursday, February 6, 2014

SIOUX FALLS, S.D. (AP) - Independent oil refiner Tesoro Corp. says it is replacing older railcars in its crude oil railcar fleet with ones that meet the latest design standards.

The company says the new cars will have more robust safety features such as improved shielding around the heads of the cars and reinforced relief valve systems.

Tesoro says 90 percent of its fleet already has those features, which meet newer design standards set by the rail industry in recent years. The company says the remaining 10 percent of the cars will be replaced by mid-2014.

Keith Casey is Tesoro’s senior vice president of strategy and business development. He says the company chose to “proactively” make these changes ahead of expected federal regulations.

Tesoro operates six refineries in the western United States.