HSIS Summary Report
Michael S. Griffith
Dec-99
This study evaluated 63 rolled-in continuous shoulder rumble strips (CSRS) in Illinois and 28 CSRS in California. Using the Illinois data, a before-and-after evaluation with yoked comparison sites was performed first. The average safety effect of CSRS was estimated to be an 18.4 percent reduction in the number of single-vehicle run-off-road crashes, with a standard deviation of 6.8 percent. Next, the Illinois data were used in a before-and-after evaluation with a comparison group. The average safety effect of CSRS on rural freeways was estimated to be a reduction of single-vehicle run-off-road crashes by 21.1 percent, with a standard deviation of 10.2 percent. A before-and-after evaluation with a comparison group was used for California. The average safety effect of CSRS was estimated to be a 7.3 percent reduction in the number of single-vehicle run-off-road crashes, with a standard deviation of 13.4 percent. Although sophisticated cost-benefit analyses were not conducted, it was estimated that one single-vehicle run-off-road crash (at an average cost of $62,200) could be prevented every three years for an investment of $217 to install one km of CSRS.
Safety Evaluation of Rolled-in Continuous Shoulder Rumble Strips Installed on Freeways
Continuous shoulder rumble strip
CSRS
Run-off-the-road crashes
Single-vehicle crashes
HSIS
HSIS Summary Reports are two to eight pages in length and include a brief description of the issue addressed, data used, methodology applied, significant results, and practical implications.
A variety of research studies have been performed using data from HSIS. Many of the final reports prepared are now available electronically.
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