The Department of Transportation needs new standards for rail cars carrying crude oil, and more action to prevent derailments, North Dakota's Sen. Hoeven said.

Hoeven said there's a growing need for the Department of Transportation and National Transportation Safety Board to impose new standards for railcars, increase inspections and work to prevent derailments in general.

"A comprehensive approach means everyone has a role -- the railroads, the regulators and the shippers, and we have to address preventing, mitigating and responding to accidents," he said in a statement Wednesday.

The NTSB said about 950 barrels of oil spilled when two trains operated by BNSF Railway collided and derailed near Casselton, N.D., in late December.

In January, the Pipeline and Hazardous Materials Safety Administration issued a safety alert saying the type of crude oil in the Bakken reserve area in North Dakota may be more flammable than other grades.

In a separate statement, U.S. Transportation Secretary Anthony Foxx said he wanted to impose new rules that would set a minimum crew size for trains carrying crude oil.

"The proposed rulemaking on crew size is the latest effort in our comprehensive strategy to ensure crude oil is transported as safely as possible," he said.

[U.S. Sen. John Hoeven]

[Department of Transportation]