Public officials in Minnesota had been warned that increasing truck traffic from international trade was placing an undue stress on the state's transportation infrastructure, including specific warnings concerning the now-collapsed bridge over the Mississippi on Interstate 35W in Minneapolis. Foreign trucks.
A Federal Highway Administration study begun in 1998 warned increased NAFTA truck traffic would endanger Minnesota bridges along I-35. A separate study by the Minnesota Department of Transportation, or MNDOT, published in May 2005a "Minnesota Statewide Freight Plan"identified the need to improve bridge and pavement deficiencies affecting trucks.
Before collapsing, the bridge was not under any restrictions, despite multiple reports of deficiencies. Overweight trucks were permitted to carry loads of up to 136,000 pounds on the interstate. Estimates are that the collapsed I-35W bridge carried 144,000 vehicles per day, including 4,760 commercial vehicles. Internal documents from MNDOT and the Dallas-based trade organization NASCONorth America's Supercorridor Coalitionshow the Minnesota agency joined NASCO to help deal with the strain NAFTA and other world trade freight loads were placing on the state's I-35 infrastructure, including support to repair the Minneapolis bridge.
In a Feb. 15, 2006, letter, Abigail McKenzie, director of the MNDOT Office of Investment Management, wrote to Melvin identifying a list of approximately 100 MNDOT requests for NASCO to assist with finding funding for the years 2007-14, including a request for $3 million to "replace overlay, joints, repair anti-icing, etc." on the I-35W bridge.
Truck traffic carries the vast majority of international trade. According to the FHWA, in 2002, trucks carried 797 million tons of international shipments, valued at approximately $1.2 trillion. By 2035, trucks are projected to carry 2.1 billion tons of international freight, valued at approximately $6.2 trillion.
The importance of international trade to I-35 has resulted in the interstate being designated as the "NAFTA Superhighway," even by prominent trade associations such as NASCO.