Cost-Benefit Analysis of Crash Cushion Systems

Abstract

Crash cushions vary in geometry and cost. In this study, crash cushions were categorized in three different categories: redirecting with repair costs greater than $1,000 (RGM), redirecting with repair costs less than $1,000 (RLM), and nonredirecting sacrificial (NRS). Typically, RGM systems are less expensive initially, but life-cycle costs are high. RLM systems typically reciprocate this trend. NRS crash cushions (e.g., sand barrels) are generally less expensive but require total replacement after a crash has occurred, which may be impractical at high-traffic volume locations. Due to limited funding, there is often a need to identify the most cost-effective crash cushion category for highway scenarios with different roadway, traffic, and roadside characteristics. This study was commissioned to determine benefit-cost ratios for each crash cushion category in a wide range of roadway and roadside characteristics using the probability-based encroachment tool, Roadside Safety Analysis Program. Only RGM and RLM systems were cost-effective for freeways and divided rural arterials, but all three categories competed against the unprotected condition on undivided rural arterials and local roads.