US rail transportation of petroleum and petroleum products for the week ended January 4 totaled 13,967 cars, up 20.2% from the same week a year ago, the Association of American Railroads said Thursday.

US railroads saw a 2.1% year-on-year increase in total carloads originated in the week ended January 4, with intermodal volumes rising 4.8%, AAR said. Intermodal traffic involves movement by more than one mode of transportation, be it rail, ship or truck.

In the most recent week, Canadian petroleum carloads rose 3.4% and Mexican petroleum carloads rose 3.6% compared with the corresponding week in 2013, AAR said.