Nevada DOT: "HSM PILOT PROJECT: SR 147- SAFETY PERFORMANCE EVALUATION"

"HSM Pilot Project: SR 147 - Safety Performance Evaluation" was presented at a poster session at the 2013 TRB Annual Meeting. Click here to view a PDF version of the poster.

Abstract:

SR 147 (Lake Mead Boulevard) is located in Clark County outside the city of Las Vegas, Nevada. The AADT (Average Annual Daily Traffic) of this two lane rural highway is 1500 vehicles per day. Over the past eight years, there have been 39 crashes on a seven-mile stretch of the highway. Seven of these 39 have been fatal crashes. NDOT is planning an improvement project and wants a substantive evaluation of alternatives to improve safety. Kimley-Horn and Associates Inc. has been contracted by NDOT to conduct a safety performance evaluation.

Three alternatives were evaluated. The first is to install a center line rumble strip. The second is to improve the horizontal geometry at a tight, reverse curve location where seven crashes have occurred in the evaluation period. The third alternative is to widen the shoulders from one foot to six feet throughout the length of the project. The project team will look for the most beneficial improvements based upon reductions in expected crashes verses improvement costs. The HSM (Highway Safety Manual) Part C – The Predictive Method is the source for estimating expected crash reductions. The Interactive Highway Safety Design Model (IHSDM) and the NCHRP 17-38 HSM predictive analysis spreadsheets were compared in their results in reductions. This project will help determine how Safety Performance Evaluation is applied to future projects in the State of Nevada.