Surface transportation trade between the U.S., Canada and Mexico dropped 33.1 percent in April 2009 from April 2008
, according to the Bureau of Transportation Statistics of the U.S. Department of Transportation. April marked the fourth consecutive month to have a yearly decline that exceeded 27 percent.

The bureau found that trade between the countries fell 2.6 percent in April from March, dropping to $49.7 billion. Month-to-month changes can be affected by seasonal variations and other factors.

Surface transportation, or freight movements by truck, rail and pipeline, accounts for about 88 percent of U.S. trade with Canada and Mexico.

In April, U.S. surface transportation trade with Canada and Mexico was down 6.5 percent from April 2004, and up 22 percent compared with April 1999, a period of 10 years. Meanwhile, imports for the month increased 19.5 percent from April 1999, while exports were up 24.9 percent.

U.S. land trade with Canada was down to $30.2 billion in April, a decline of 38.2 percent versus April 2008. Truck imports dropped 32.8 percent compared with April 2008, while the value of exports was 31.2 lower during this period. Michigan topped the list of states in surface trade with Canada with $3.3 billion in April.

Surface trade between the U.S. and Mexico amounted to $19.5 billion, a drop of 23.4 percent below April 2008 levels. Imports by truck were down 22 percent from April 2008, and exports were 18 percent lower. Texas came out on top in terms of U.S.-Mexico land trade, with $6.6 billion.