A measure of freight moving between the U.S. and its neighbors to the north and south shows for the first time the total value of U.S.-Mexico freight flows exceeded those between the U.S. and Canada.

According to new U.S. Transportation Department figures, the value of U.S.-Canada freight totaled $47.7 billion in October, down 18.5% from a year earlier, the largest drop since the 19.4% decline between October 2008 and October 2009.

This compares to the value of U.S.-Mexico freight totaling $48.9 billion in October, down 1.5% from October 2014, as two out of the five transportation modes, air and truck, carried more U.S.-Mexico freight than in October 2014.

The overall value of U.S.- Canada and Mexico freight totaled $96.6 billion in October 2015 as all modes of transportation carried a lower total value of freight than a year earlier.

In October 2015 compared to a year earlier, the value of commodities moving by truck decreased by 2%, while the value of air freight decreased by 2.1% and rail by 15.3%. Vessel freight and pipeline values posted even larger declines, all mainly due to the lower prices for crude oil, which comprises a large share of the commodities carried by these modes.

Apart from the decline in value, there was an 8% decline in the weight of imported crude oil in October year-over-year, which was likely due to production declines in Canada and Mexico.

Trucks carried 61.2% of the freight to and from Canada. The surface transportation modes of truck, rail and pipeline carried 83.9% of the total U.S.-Canada freight flows.

In October, the top commodity category transported between the U.S. and Canada by all modes was vehicles and parts, of which $5.7 billion, or 62.1 percent, moved by truck and $3.2 billion, or 35.6 percent, moved by rail.

Trucks carried 72.8% of the $48.9 billion of the value of freight transported to and from Mexico as the surface transportation modes of truck, rail and pipeline carried 86.7% of the total U.S.-Mexico freight flows.

The top commodity category for all modes transported between the U.S. and Mexico in October 2015 was electrical machinery, of which $10.1 billion, or 93%, moved by truck.