1 Journal of Borderlands Studies Volume 23 • No. 2 • Summer 2008 Spatial Equity and Transportation Hazard Along Cross-Border Trade Corridors: The Case of Ambos Nogales Francisco Lara-Valencia, Juan Declet-Barreto and Eric Keys* Abstract: Using a spatial perspective, this article explores the equity dimension of the North American Free Trade Agreement (NAFTA) in Nogales, Sonora and Nogales, Arizona, two of the U.S.-Mexico border communities most impacted by trade after the implementation of the agree- ment in 1994. Ambos Nogales (Both Nogales) is a major hub within the cross-border transpor- tation corridor connecting northwestern Mexico with the United States and Canada and both cities are subject to intense trade-related traffic, including the movement of hazardous materials and toxic waste generated by export-oriented industries in Mexico. As a first step in this analy- sis, we classify and map residential areas in Ambos Nogales applying an index of socio-environ- mental vulnerability. We then define the boundaries of existing hazard zones and their overlay with these areas in both cities. Finally, we contrast residential areas within the hazard zones with those outside to probe for patterns of social inequity both locally and across the border. Introduction Trade and foreign investment between the U.S. and Mexico have increased sub- stantially in the wake of the ratification the North American Free Trade Agreement (NAFTA) in January 1994. From 1993 to 2005, U.S.-Mexico total trade increased 256%, from $81.5 to $290.5 billion (U.S. Bureau of the Census 2007). U.S. foreign direct investment (FDI) into Mexico quadrupled after the implementation of NAFTA from an average of $2.1 billion between 1986 and 1993 to an annual average of $8.5 billion between 1994 and 2003 (Secretaría de Economía 2006). Although U.S. FDI in Mexico targets a diversity of activities, the manufacturing sector absorbs more than half of this inflow of capital. Perceiving potential benefits from trade and capital flows catalyzed by the NAFTA, many communities along the U.S.-Mexico border engaged in the creation of coalitions and public-private partnerships, promoting trade through the formation of cross-bor- der corridors extending from Canadian cities, passing through large metropolitan mar- kets in the U.S. and ending up in Mexico City (Harrison and McRay 1999). The main goal of these partnerships is the development of a “seamless and efficient” transporta- tion network by upgrading existing infrastructure, as exemplified by the expansion of roads or the opening of new international crossings in several border cities (CANAMEX We thank the North American Center for Transborder Studies (NACTS) and the Southwest Center for Environ- mental Research and Policy (SCERP) for the financial support provided for the completion of this research. *Lara-Valencia is Assistant Professor in the School of Planning at Arizona State University. Declet-Barreto is a graduate student in the School of Geographical Sciences at Arizona State University. Keys is Assistant Professor in the Department of Geography at the University of Florida.