"Railroads, coal companies and electric utilities have cooperated all year to make sure that coal supplies would be sufficient to keep electricity flowing in all kinds of weather," said Edward R. Hamberger, Association of American Railroads chief executive officer.

Coal exports are also "booming" the report said, reaching almost 60 million tons in 2007, "the most in nine years."

Hamberger said railroads have spent "billions" to increase their capacity for carrying coal and the industry expects expansions to continue.

The demand for rail freight service could double by 2035, the report said.