Proximity to Mexico led Caltrans to open two state-of-the-art commercial inspection facilities in Border Division, one at Otay Mesa and the other at Calexico. Each facility cost $16 million. The facilities handle the increased truck traffic arriving from south of the border generated by the North American Free Trade Agreement (NAFTA). These facilities, located in San Diego and Imperial counties, operate jointly with the US Customs Service, inspecting thousands of trucks yearly to assure they are mechanically ready for California's highways.
Ulmer Industries furnished the structure at the Otay Mesa facility to accommodate the radiation detection components needed to scan the trucks bringing commerce into the USA from Mexico.