Optimization of site locations for a Road Weather Information System in Austin, Texas based on inclement weather crashes

For this project, an optimization scheme was developed to locate Road Weather Information System (RWIS) stations along the Interstate Highway 35 (IH-35) corridor for the Austin TxDOT district. In order to do this, eight major roadways in the three counties, Williamson, Travis, and Hays, that IH-35 passes through were chosen for analysis. Four north-south highways were selected, IH-35, SH-130, SL-1, and US-183, and four east-west highways were selected, SH-45, US-79, US-290, and SH-71. Crash Record Information System (CRIS) crash data was used to determine crashes that happened along these routes between 2006 and 2011 during inclement weather conditions. Routes were broken up into segments of equal lengths and crash rates were determined using TXDOT AADT information. These crash rates were calculated over a smoothing distance larger than the segment distances to provide more consistent rates and optimal locations were determined using a maximization algorithm based on the crash rate for these segments and their distance away from the sensor locations. Applying different segment lengths, smoothing distances, and crash data in analysis yielded varying optimal locations that were analyzed based on coverage area within the three county analysis region based on a 10 mile radius of coverage for each station.