While Minnesota has made much progress in reducing traffic fatalities, rural stop-controlled intersections remain an ongoing challenge. The Minnesota Department of Transportation (MnDOT) launched the Rural Intersection Conflict Warning System (RICWS) deployment project in 2012 to work toward reducing crashes at such intersections.
The three-year project will deploy intersection conflict warning systems at up to 50 rural stop-controlled intersections statewide.
U of M researchers recently evaluated the first installation, using technology developed in previous research to monitor the RICWS and demonstrate its accuracy and reliability.
Intersection conflict warning systems (ICWS) give drivers on both the major and minor road a dynamic warning of approaching vehicles. A variety of types of ICWS have been developed and tested in many states. Early results from these tests show a 30 percent reduction in total crashes and greater reductions for fatal and serious injury crashes.
The researchers evaluated the system selected for MnDOT’s RICWS for 34 days at the intersection of Trunk Highway 7 and Carver County CSAH 33. They installed a portable intersection surveillance system (ISS) and collected data from the RICWS and the ISS. They then validated data collected from the RICWS against data recorded by the ISS to determine the accuracy and reliability of the RICWS.
The researchers determined that the RICWS had a sign activation rate of 99.98 percent (or 1 vehicle per 5,000 vehicles), meeting the 99.95 percent rate specified by MnDOT. The research team also validated sign activations using video captured at the site and recorded a sample of times for valid activations and valid periods when the sign was inactive.
“The 99.98 percent activation reliability is great news,” says Ken Hansen, RICWS deputy project manager with MnDOT. “By using dual vehicle detection, we are able to give the traveling public confidence in RICWS systems. With the reliability information, MnDOT plans to start new projects to install more RICWS across the state.”
Read the full article in the August issue of Catalyst.