The number of railcars carrying crude oil surged 83 percent last year over 2012 levels.
The bump in crude-by-rail comes as concerns surrounding the shipments of crude oil by train are increasing due to multiple accidents.
The Association of American Railroads said major U.S. railways delivered 434,042 carloads of crude oil in 2013, The Associated Press reports.
That's nearly double the amount shipped in 2012, which came in at 236,556 carloads of crude oil. All together crude-by-rail has grown substantially from 2008 levels, which totaled 9,344 carloads.
Lawmakers are making more noise in Washington about stricter standards for tankers carrying crude oil. They are also pressing federal regulators to conduct tests on the crude oil, which regulators have speculated could be more flammable than other types of crude.