Crash analysis of I-64 closure in St. Louis county.

PDFTech Report25-1121-0001-341Interstate highwaysLane closureHighway safetyAccident ratesAccident analysisWork zonesSpeed limitsTraffic diversionMissouriMid-America Transportation CenterMissouri. Dept. of TransportationBham, Ghulam H.Manepalli, Uday R.R.Missouri University of Science and Technology. Dept. of Civil, Architectural, and Environmental EngineeringUnited States. Federal Highway AdministrationUnited States. Dept. of Transportation. Research and Innovative Technology AdministrationNTL-HIGHWAY/ROAD TRANSPORTATION-Construction and MaintenanceNTL-OPERATIONS AND TRAFFIC CONTROLS-OPERATIONS AND TRAFFIC CONTROLSNTL-SAFETY AND SECURITY-Highway SafetyNTL-SAFETY AND SECURITY-AccidentsUS Transportation CollectionOn January 2, 2008, the Missouri Department of Transportation (MoDOT) closed significant portions of Missouri Interstate 64(I-64) in St. Louis County for reconstruction. During the planning stages of this project, the proposal to close all lanes of I-64was met with public concern regarding the possible safety risks associated with diverting I-64 traffic to adjacent roadways. Aspecific concern was the possibility of increased crash rates on roads designated to receive I-64 traffic flow. The followingresearch was conducted to assess the actual outcomes related to these concerns. Crash analyses and crash rate analysis of 2008and 2009 crash data were performed. The data were compared to four years of pre-closure crash data. Overall results suggestno evidence of increased crash rates on roadways adjacent to I-64 resulting from the two-year closure period. The studyindicated that crash rates on 17 roadways were 8.9% below average in 2008 and 14.7% below average in 2009. Crash ratesdeclined for most freeways, expressways, and major arterials in the surrounding region. Rear-end crashes declined noticeablyfrom 7,757 in 2007 to 6,728 in 2009