Browsing by Subject "highway safety"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Development of a Queue Warning System Utilizing ATM Infrastructure System Development and Field-Testing
    (Minnesota Department of Transportation, 2017-06) Hourdos, John; Liu, Zhejun; Dirks, Peter; Liu, Henry X.; Huang, Shihong; Sun, Weili; Xiao, Lin
    MnDOT has already deployed an extensive infrastructure for Active Traffic Management (ATM) on I-35W and I-94 with plans to expand on other segments of the Twin Cities freeway network. The ATM system includes intelligent lane control signals (ILCS) spaced every half mile over every lane to warn motorists of incidents or hazards on the roadway ahead. This project developed two separate systems that can identify lane-specific shockwave or queuing conditions on the freeway and use existing ILCS to warn motorists upstream for rear-end collision prevention. The two systems were field tested at two locations in the ATM equipped network that have a high frequency of rear- end collisions. These locations experience significantly different traffic-flow conditions, allowing for the development and testing of two different approaches to the same problem. The I-94 westbound segment in downtown Minneapolis is known for its high crash rate due to rapidly evolving shockwaves while the I-35W southbound segment north of the TH-62 interchange experiences longstanding queues extending into the freeway mainline. The Minnesota Traffic Observatory developed the I-94 Queue Warning system while the University of Michigan, under contract, developed the I-35W system. Prior to the I-94 installation, based on data collected in 2013, there were 11.9 crashes per VMT and 111.8 near crashes per VMT. In the first three months of the system’s deployment, event frequency reduced to 9.34 crashes per million vehicle miles of travel (MVMT) and 51.8 near crashes per MVMT, a 22% decrease in crashes and a 54% decrease in near crashes. The I-35W system did not undergo a similarly thorough evaluation, but for most of the lane segments involved, it showed that queue warning messages help reduce the speed variance near the queue locations and the speed difference between upstream and downstream locations. This also implicated a satisfactory level of compliance rate from travelers.
  • Thumbnail Image
    Item
    Five-County Minnesota Case Study: Rural Roadway Fatal Crash Characteristics and Select Safety Improvement Programs
    (Center for Excellence in Rural Safety, Hubert H. Humphrey Institute of Public Affairs, University of Minnesota, 2008-12) Patterson, Tyler M.; Munnich, Lee
    This second in a series of CERS research reports summarizes the characteristics of the fatal rural roadway crashes within five Minnesota counties and describes some of the safety improvement programs or campaigns being used in this five-county area. Past research has shown that some of the many characteristics of fatal rural roadway crashes include younger drivers, alcohol involvement, lack of seat belt use, and speeding. The crash data summarized in this report were generally obtained from the Minnesota Department of Transportation and Minnesota Department of Public Safety. Several recommendations have been proposed as a result of this case study project that focus on improving rural roadway safety data and analyses. Evaluations of safety improvement programs/campaigns are also proposed. Recommendations include: • Examine more rural roadway crash factors and combinations of factors for additional clarification. • Improve the metrics used to describe or define rural roadways in the United States. • Use the primary characteristics of rural roadway crashes as the basis for safety improvement measures and programs implemented in rural areas. • Include measures and strategies that improve driver decision-making as one of the focus or emphasis areas of a comprehensive safety program. • Fund projects that continue to help upgrade and apply GIS tools to plot and evaluate safety data with respect to driver behavior and roadway conditions. • Scientifically evaluate the impacts of the safety improvement programs described in this report.