Evaluation of Intersection Conflict Warning Systems

Rural intersections account for 30% of crashes in rural areas and 6% of all fatal crashes. One unique and promising solution has been to use intersection conflict warning systems (ICWS) at the minor approach of stop-controlled intersections. Early studies indicate lower intersection approach speeds, reduced conflicts, improved compliance with traffic control, and improved gap selection. Simple before and after crash analyses have indicated reductions in total crashes up to 46% and severe crashes up to 72%. However, there has been some evidence of increased roll-throughs, and some sites have experienced minor crash increases. Although ICWS show promise, their effectiveness has not been well established. Since robust crash analyses are not yet available, it is desirable to evaluate the systems using crash surrogates so that further investments can be considered. Additionally, the influence of ICWS on adjacent intersections has not been considered. As a result the objectives of this research are to: Evaluate driver behavior at mainline and stop-controlled approaches for intersections with and without ICWS. Develop an assessment of the traffic volume range and limits where the system is nearly continuously activated and is likely to lose its effectiveness.


  • English


  • Status: Completed
  • Funding: $278,516.00
  • Contract Numbers:

    99004 WO#16

  • Sponsor Organizations:

    Minnesota Department of Transportation

    395 John Ireland Boulevard
    St Paul, MN  United States  55155
  • Project Managers:

    Rindels, Alan

  • Performing Organizations:

    Iowa State University, Ames

    Ames, IA  United States  50011
  • Principal Investigators:

    Hallmark, Shauna

  • Start Date: 20140630
  • Expected Completion Date: 20180630
  • Actual Completion Date: 0
  • Source Data: RiP Project 38093

Subject/Index Terms

Filing Info

  • Accession Number: 01543725
  • Record Type: Research project
  • Source Agency: Minnesota Department of Transportation
  • Contract Numbers: 99004 WO#16
  • Files: RiP, STATEDOT
  • Created Date: Nov 21 2014 1:01AM