Trucking and four other transportation modes carried less U.S. freight by value with North American Free Trade Agreement (NAFTA) partners Canada and Mexico in March 2016 compared to a year earlier, according to a new Transportation Department report.

The total value of cross-border freight moved fell 5.8% to $90.5 billion as the value of commodities moving by truck declined 1.1%, the smallest decrease from 2015 to 2016 of any mode.

The value of freight carried on other modes also declined: rail, 7.7%; air, 9%; vessel, 31.9%; and pipeline, 33.2%.

“A drop in the price of crude oil played a key role in the large declines in the dollar value of products shipped by vessel and pipeline,” the department said. “Crude oil comprises a large share of the commodities carried by these modes.”

Trucks carried 67.3% of U.S.-NAFTA freight and continued to be the most heavily utilized mode for moving goods to and from both U.S.-NAFTA partners. They accounted for $31.4 billion of the $48 billion of imports, or 65.3%, and $29.5 billion of the $42.5 billion of exports, or 69.4%.

Rail remained the second largest mode by value, moving 15.5% of all U.S.-NAFTA freight.

From March 2015 to March 2016, the value of U.S.-Canada freight flows fell 8.8% to $46.4 billion as all modes of transportation carried a lower value of U.S.-Canada freight than a year earlier.

Trucks carried 62.1% of the value of the freight to and from Canada while rail carried 17%. The top commodity category transported between the U.S. and Canada by all modes was vehicles and parts, of which $5.3 billion, or 55.4%, moved by truck.

During this same year-over-year March period, the value of U.S.-Mexico freight fell 2.6% to $44.1 billion as all modes of transportation except truck carried a lower value of U.S.-Mexico freight than a year earlier.

Freight carried by truck increased 0.7%, primarily because of an increase in shipments of computers and parts, according to the department. Rail freight value declined 8.6% while air freight value declined 10.1%. Pipeline freight value dropped by 14.2%, while vessel freight value decreased by 18.9%.

Trucks carried 72.7% of the value of freight to and from Mexico while rail carried 14% The top commodity category transported between the U.S. and Mexico by all modes was electrical machinery, of which $7.7 billion, or 91.3%, moved by truck.