Guidance on the application of cable median barrier: tradeoffs between crash frequency, crash severity, and agency costs

dc.contributor.advisor Peter T. Savolainen Russo, Brendan
dc.contributor.department Civil, Construction, and Environmental Engineering 2018-08-11T09:10:30.000 2020-06-30T02:57:56Z 2020-06-30T02:57:56Z Thu Jan 01 00:00:00 UTC 2015 2001-01-01 2015-01-01
dc.description.abstract <p>Median-crossover crashes present the highest risk of fatality and severe injury among collision types on freeways. These crashes can be caused by a variety of factors, including drowsiness, driver distraction, impaired driving, and loss of control. The primary countermeasure to reduce the opportunity for such crashes is the installation of median barriers. The Michigan Department of Transportation (MDOT) began installing high- tension cable median barriers in 2008, and has installed approximately 317 miles of cable median barrier on state freeways as of January 2014. Given the capital costs required for this installation program, a comprehensive before-after evaluation was conducted in order to ascertain the efficacy of cable barrier systems installed to date, and to develop guidelines to identify candidate locations for subsequent installations.</p> <p>Crash reports were reviewed to identify target median-related crashes and this manual review provided critical supplementary information not normally available from the standard fields on police crash report forms. Statistical analyses which accounted for regression-to-the-mean effects showed that fatal and incapacitating injury crashes were reduced by 33 percent after cable barrier installation. The analysis also showed the median cross-over crash rate was reduced by 86.8 percent and the rate of rollover crashes was reduced by 50.4 percent. In contrast, less severe crashes were found to increase by 155 percent after cable barrier installation. A detailed analysis of crashes involving a cable barrier strike found the barriers were 96.9 percent effective in preventing penetration through the barrier. Weather conditions, horizontal curvature, and offset of cable barrier from the roadway were also found to play a role in the frequency and severity of crashes, as well as cable barrier performance.</p> <p>In addition to cable barrier segments, comparison roadway segments with thrie-beam guardrail and concrete median barriers were also analyzed as part of this research. Statistical models were developed to analyze factors affecting crash frequency, crash severity, and barrier strike outcomes among all three median barrier types. This study provides one of the first comprehensive analyses of thrie-beam median guardrail using observed highway-crash data, as most previous studies have focused on the more common w-beam guardrail.</p>
dc.format.mimetype application/pdf
dc.identifier archive/
dc.identifier.articleid 5621
dc.identifier.contextkey 8049372
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath etd/14614
dc.language.iso en
dc.source.bitstream archive/|||Fri Jan 14 20:23:34 UTC 2022
dc.subject.disciplines Civil Engineering
dc.subject.disciplines Transportation Engineering
dc.subject.keywords Civil Engineering (Transportation Engineering)
dc.subject.keywords Civil Engineering
dc.subject.keywords Transportation Engineering
dc.subject.keywords Cable Median Barrier
dc.subject.keywords Crash Frequency
dc.subject.keywords Crash Severity
dc.subject.keywords Empirical Bayes
dc.title Guidance on the application of cable median barrier: tradeoffs between crash frequency, crash severity, and agency costs
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication dissertation Doctor of Philosophy
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