Mexico Trucker Online  Check the lower right of the home page for very useful links concerning the NAFTA as it relates to the free circulation of trucks in the US and Mexico.

Federal Motor Carrier Safety Administration (FMCSA), NAFTA - Transportation Related Provisions  A summary of the provisions of the NAFTA regarding truck circulation (cabotage) in Mexico and the US.

Published in Transportation Journal, June 22, 1994 U.S. motor carrier perspectives on trucking to Mexico., by Michael R. Crum of Iowa State University, provides an extensive, and academically sound, review of US truckers' concerns about operating in Mexico. Most probably, little has changed in the intervening decade and a half.