Evaluation of Centerline Audible Roadway Delineators (CARDs) in New York State

Abstract

This study evaluated the safety effectiveness of the systemic implementation of centerline rumble strips on New York State-owned roads. In New York State, rumble strips installed on the centerline are referred to as centerline audible roadway delineators (CARDs). The effect of CARDs on head-on sideswipe (HO/SS), run-off-road (ROR), injury crashes, and fatal crashes was analyzed. This was an observational, naïve before–after with comparison group study. The treatment group included all segments where CARDs were installed in 2013, 2014, and 2015 in New York State Department of Transportation Regions 1 and 4, and Dutchess County in Region 8. Eligible segments without CARDs in those regions constituted the control group. The crashes comprised 2009 to 2017 HO/SS and ROR fatal, all injury, and property damage only crashes. The study showed that CARDs are an effective treatment to reduce ROR and HO/SS crashes. There was a decrease of 24 ROR and 9 HO/SS crashes on CARDs segments installed in 2013, a decrease of 12 ROR and 27 HO/SS crashes on CARDs segments installed in 2014, and a decrease of 40 ROR and 35 HO/SS crashes on CARDs segments installed in 2015. Crash modification factors (CMFs) developed for CARDs included ROR crashes (a CMF of 0.774 [expected reduction of 22.6%] in all ROR crashes); HO/SS crashes (a CMF of 0.623 [expected reduction of 37.7%] in HO/SS total crashes); and HO/SS injury crashes (a CMF of 0.572 [expected reduction of 42.8%] in injury HO/SS crashes).