The City and County of San Francisco Airports Commission adopted a Master Plan for various improvement projects for the San Francisco International Airport to be implemented through the year 2006. The Master Plan includes the Airport Rail Transit (ART) project. The ART is a fully automated guideway transit system, similar to systems operating at a number of airports internationally and in the U.S. This transit system is now called the SkyTrain.

The SkyTrain project covers the preliminary and detailed design engineering, and preparation of construction bid documents for a 1.25 mile long loop of elevated dual guideways connecting the existing terminals with the new International Terminal and new Parking Garages, and fixed facilities that comprise station platform structures, equipment rooms, safety walkways and other miscellaneous civil/structural installations. The project also includes a single guideway spur to the interim maintenance facility on Lot CC. Transit Guideway Consultants (TGC) was the prime consultant for this project. TCG selected OPAC to provide engineering services for this project.