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.
Research reports are often summarized in executive summaries, technical briefs, or other abbreviated formats. Included here are those road safety summaries that involved research using HSIS data.
In addition to conducting research, HSIS resources are also used to develop products that can be used by practitioners in the analysis of safety problems.
HSIS data are sometimes used in research studies that result in other types of finished products, such as dissertations, theses, and conference proceedings.
