The volume of crude oil transported by rail in the United States is greater than the volume in Canada by a factor of nearly 9-to-1, federal data show.

In a first, the U.S. Energy Information Administration said it was now publishing monthly data on the volume of crude oil transported on regional railways.

"The new crude-by-rail data provides a clearer picture on a mode of oil transportation that has experienced rapid growth in recent years and is of great interest to policy makers, the public, and industry," EIA Administrator Adam Sieminski said in a statement Monday.

U.S. oil production has accelerated at a faster pace than at any other time since record-keeping began more than 100 years ago. The growth rate is more than the existing network of oil pipelines can handle, forcing many in the energy industry to rely on rail to make up for the shortfall.

EIA data show a total 1.05 million barrels of crude oil were transported on the U.S. and Canadian railway systems in January, the last full month for which the federal government has data. Of that, about 87 percent of the oil was moved on the U.S. rail system and most of that was in the Midwest.

The increase in rail traffic has coincided with a rise in derailments involving trains carrying crude oil.

Several cars carrying crude oil through Ontario derailed March 7. Kathy Fox, chair of the Transportation Safety Board of Canada, said she was concerned about the lack of adequate safety standards, adding it was time to replace or retrofit existing tanks cars.

More than 40 people were killed in a 2013 oil-train derailment in Lac-Megantic, Quebec.

A crash involving a CSX train carrying crude oil through West Virginia involved newer CPC-1232 model rail cars. The U.S. Pipeline and Hazardous Materials Safety Administration found CPC-1232 were "marginally" better than older cars involved in the Canadian derailments.