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167555-1 Report Abstract

Characterizing Truck Traffic in the U.S.-Mexico Highway Trade Corridor and the Load Associated Pavement Damage

Feng Hong, Jolanda P. Prozzi, and Jorge A. Prozzi, University of Texas at Austin, April 2007, 58 pp. (167555-1)

As the biggest asset in the transportation infrastructure system, highways play a critical role in a nation’s economic development. Paradoxically, while this development serves as a driving force it is also responsible for significant damage to the highway infrastructure.

The United States, together with Mexico and Canada, signed the North American Free Trade Agreement (NAFTA) in 1992 in an effort to eliminate a large number of tariff barriers to free trade and thus to enhance the economic development of the three countries. Since the ratification of NAFTA in November 1993, U.S. trade with Canada and Mexico has increased dramatically, resulting in a significant increase in truck movements in the countries. In 2004, the Supreme Court ruled against the requirement to undertake an environmental impact study before opening the U.S.-Mexico border, which paved the way for U.S. roads to be opened to long-haul Mexican carriers under NAFTA.

As a result of truck traffic surge, from the perspective of infrastructure preservation, concerns have been raised by highway agencies in the bordering states regarding the increased damage by the growing traffic.

Because of Texas’ proximity to the industrial heartlands of both Mexico and the U.S., the Texas transportation infrastructure is perhaps more affected by the dynamics of free trade than any other state in the U.S. This study is conducted through historical traffic data collected in the U.S.-Mexico trade corridor in Texas. Axle load distributions were investigated in terms of their spatial and temporal characteristics. The main statistical features of traffic loadings, with respect to their damaging effects on highway infrastructure, are captured. An evaluation is presented regarding the prediction of traffic loads, which is not only based on historical data but also accounts for other relevant aspects involving policy and weight limit regulations.

The results presented in this report can furnish highway agencies with better evaluation tools for highway infrastructure management in the trade corridor. The findings could also facilitate policy decisions regarding truck weight regulations and border openings to foreign traffic. To this end, a balance between rational highway infrastructure deterioration and efficient truck freight transportation can be reached.

Keywords: U.S.-Mexico Trade, NAFTA, Truck Volumes, Vehicle Classification, Axle Loading, Weigh-in-Motion

ENTIRE REPORT (Adobe Acrobat File – 1.5 MB)