Hypothetical Analysis on Cost Effectiveness of Centerline Rumble Strips as a Crash Countermeasure

Abstract

Rural roads are mostly undivided highways with high speed, two-way traffic. These factors coupled with inattentive driver behavior increase the risk of frontal and sideswipe collisions. Widening of roads and installation of barriers or medians are expensive improvement options. Centerline Rumble Strips (CLRS) are a costeffective countermeasure for reducing head-on and sideswipe crash types by warning distracted drivers of lane departures that lead to an intrusion onto the adjoining lane through tactile stimuli. This study documents the state-of-the-practice pertaining to CLRS across the U.S. and attempts to establish a selection criterion for identifying locations that warrant CLRS installations. Using this selection criterion in the Critical Analysis Reporting Environment (CARE) software, candidate segments warranting CLRS installations in the State of Alabama were identified. Further, an economic analysis was conducted to determine the benefit to cost ratio for the selected locations by attaching a monetary value to individual crash types, namely fatal, injury, and property damage only (PDO) and comparing them to the cost of a CLRS installation. A 14% reduction in the number of crashes was the expected tangible benefit of CLRS. This value was selected from the Insurance Institute of Highway Safety (IIHS) study of 2003. According to this study, “reliable” data from 7 states with a total 210 miles of CLRS was analyzed and it was concluded that sites treated with CLRS had an overall reduction of 14% in lane crossover crash types. Therefore, the number of crashes represented by the 14% were determined for every segment. The savings in crash cost due to the 14% crashes that would be prevented was the expected benefit of CLRS. The monetary amount incurred due to the installation of CLRS was the only cost that was associated with CLRS. Some other factors which may affect the cost of installation could be the cost of traffic control and speed at which the CLRS installation is performed. Cost of installation from the surveys was found to be $0.55/linear foot and was the only cost that was associated with CLRS in this report. The value of the benefit to cost ratio was found to be 16.5 which establishes CLRS as a cost-effective crash countermeasure. Finally, the segments were prioritized based on the crash rates experienced on the individual segments.