Study says partnership between Wayne State and State of Michigan is saving lives on highways
A recently completed study by the Wayne State College of Engineering's Transportation Research Group (WSU TRG) shows that rumble strips are proving to be an effective and low-cost way to reduce crashes on Michigan's state highways.
"Rumble strips are a proven, cost-effective countermeasure to lane departure crashes brought on by driver drowsiness, distraction and/or inattention," the WSU TRG's report said. "We can project…this initiative in Michigan will result in an annual reduction of 337 crashes, saving 16 lives and 62 serious injuries each year."
In 2008, the Michigan Department of Transportation (MDOT), acting on the recommendation of a previous Wayne State TRG study, started a major rumble strip program for two-lane, high-speed rural highways. Centerline and shoulder rumble strips were installed on all MDOT rural, non-freeway highways with posted speed limits of 55 mph and appropriate paved lane and shoulder widths. To date, MDOT has placed 5,700 miles of centerline rumble strips and 1,700 miles of shoulder rumble strips.
MDOT approached Wayne State's TRG to conduct a study assessing the success of this transportation initiative. The study ultimately found significant reductions in several targeted categories of crashes, including head-on, sideswipe and run-off-the-road crashes. In the categories examined, the study showed a 47 percent reduction in total crashes and a 51 percent reduction in fatal crashes.
"This study is one of the largest and most comprehensive investigations of effectiveness of any safety countermeasure that has ever been performed at a state level," said Tapan Datta, a WSU civil and environmental engineering professor and principal investigator of the research project. "Analyzing all of MDOT's two-lane, high-speed highways with rumble strip treatments targeted to alleviate lane departure-related traffic crashes makes the results real and reliable. They can be used by other states to establish their own rumble strip programs."
Datta said future research should focus on use of rumble strips on two-lane country roads and multi-lane, non-freeway, high-speed roads.
These safety gains aren't coming at great cost to taxpayers. The report's economic analysis of the rumble strip program showed a high benefit-to-cost ratio. Depending on how the cost was spread out over time, the ratio was between 58:1 and 18:1. Researchers estimated a total safety benefit of more than $79 million over three years.
In a previous rumble strip study completed in 2012, WSU's TRG found that the presence of centerline rumble strips improves driver performance in most conditions. Drivers position themselves more centrally in lanes, leading to fewer encroachments over centerlines and shoulders, thus increasing safety. And while drivers generally tended to ride onto or across the centerline when passing bicyclists, they did so less frequently when centerline rumble strips were present. They also found that centerline rumble strips did not contribute to short-term cracking in asphalt pavements. Further, rumble strips typically produced no more noise than that made by tractor-trailer trucks traveling on normal highways.
Read the full rumble strip report
http://www.uppermichiganssource.com/news/story.aspx?id=1212036#.VWyf189Vgg0
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Wayne State University is a premier urban research institution of higher education offering 380 academic programs through 13 schools and colleges to nearly 28,000 students. For more information about engineering at Wayne State University, visit engineering.wayne.edu.