Ping.
Nearly all of the oil tank cars are owned/leased by oil companies. The railroad is hired to move them.
In order to help convince those using the older design (less safe) tank cars, BNSF (and others) has added a surcharge to cover the risk.
BNSF to add surcharge to older tank cars
http://www.freerepublic.com/focus/f-news/3219681/posts
October 24, 2014
BNSF Railway Co. plans to apply a $1,000 surcharge for each older tank car that hauls oil, as the railroad owned by Warren Buffett’s Berkshire Hathaway Inc. encourages shippers to scrap the puncture-prone cars.
The charge, which will take effect Jan. 1, will add about $1.50 per barrel to the cost of shipping oil across the country.