A comprehensive research program for the characterization of storm water runoff from an Arizona highway was conducted from January through December 2007. The study area covered a portion of the Loop 202 freeway west of Mesa Drive to a retention basin east of Lindsay Road in Mesa, Arizona. Storm water samples were collected from two storm water detention basins and a discharge point to the Salt River. The study was conducted by manually collecting storm water samples with passive automatic samplers and analyzing them for various roadway constituents. A primary objective of this research effort was to establish baseline values of constituents in ADOT highway runoff, aiding in the evaluation of related best management practices. A total of 16 storm water samples was collected from the research area between January 2007 and December 2007.