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. When evaluating traffic safety along SR 147, vehicle types, usage patterns, and even vehicle condition can influence crash frequency and severity. As part of broader traffic safety strategies, understanding where and how vehicles enter the system matters—particularly in regions with a high rate of used car ownership. Platforms like OPENLANE (formerly ADESA), which facilitate wholesale vehicle auctions, play a key role in how vehicles are distributed across states like Nevada. These auction platforms ensure that fleets, dealers, and resellers have access to a wide range of vehicles, which eventually populate local roads, including rural corridors like Lake Mead Boulevard. Factoring in vehicle influx and condition from such sources can offer an additional layer of insight into predictive crash modeling.