Development of a Queue Warning System Utilizing ATM Infrastructure System Development and Field-Testing

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.

• Record URL:
  http://dot.state.mn.us/research/reports/2017/201720.pdf
• 
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/32637
• Corporate Authors:

  University of Minnesota, Twin Cities

  Department of Civil, Environmental and Geo-Engineering
  500 Pillsbury Drive SE
  Minneapolis, MN  United States  55455

  Minnesota Local Road Research Board

  Mn/DOT Office of Research Services, 395 John Ireland Boulevard
  St Paul, MN  United States  55155
• Authors:
  • Hourdos, John
  • Liu, Zhejun
  • Dirks, Peter
  • Liu, Henry X
  • Huang, Shihong
  • Sun, Weili
  • Xiao, Lin
• Publication Date: 2017-6-13

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Figures; Photos; References; Tables;
• Pagination: 86p

Subject/Index Terms

• TRT Terms: Crash rates; Field tests; Highway safety; Highway traffic control; Physical distribution; Rear end crashes; Traffic flow; Traffic queuing; Warning systems
• Uncontrolled Terms: Active traffic management
• Geographic Terms: Minneapolis (Minnesota); Twin Cities Metropolitan Area (Minnesota)
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 01641191
• Record Type: Publication
• Report/Paper Numbers: MN/RC 2017-20
• Contract Numbers: (C) 99008 (wo) 154
• Files: NTL, TRIS, ATRI, STATEDOT
• Created Date: Jul 18 2017 5:13PM