The Association of American Railroads said deliveries of petroleum products by rail increased 170,994 carloads in 2012 from the previous year, a 46.3 percent increase.
AAR said the largest declines for 2012 when compared to the previous year came from coal, which saw deliveries drop 10.8 percent.
"Coal and grain typically account for around half of U.S. rail carloads, so when they're down, chances are good that overall rail carloads are down too, as we saw in 2012," AAR Senior Vice President John Gray said in a statement.
AAR said carload traffic overall fell 3.1 percent from 2011.
Oklahoma natural gas company Oneok Partners in November scrubbed plans for a pipeline to carry 200,000 barrels of oil per day from the Bakken play in North Dakota because of lack of interest. Enbridge, however, has committed to a $68 million rail system near Philadelphia that can handle up to 80,000 barrels of oil per day from the Bakken play.
The oil boom in the United States, brought on in part by shale developments, is outpacing pipeline capacity in the country.