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.

Project Summary

Passing and climbing lanes provide additional lanes for vehicles to safely pass other vehicles while maintaining speeds. Implementing passing and climbing lane projects provides traffic operational and safety benefits at a cost that is far less than fully widening a highway. In an effort to enhance safety and mobility on Arizona's roadways, the Arizona Department of Transportation is currently updating the 2003 Passing and Climbing Lanes Prioritization Study. This update intends to further refine the identification and prioritization methodology previously utilized and to develop a prioritized list of candidate locations that would provide the most benefit to the traveling public.
Study Objectives

    Review previous studies and research current best practices.
    Analyze the safety and performance benefits of passing/climbing lanes constructed since the previous study.
    Develop a revised methodology and ranking criteria.
    Obtain feedback from ADOT District Engineers and other stakeholders, such as rural COGs and MPOs.
    Develop a new prioritized list of candidate passing/climbing lane projects.