Intersection crashes continue to represent a significant share of transportation fatalities and serious injuries throughout the country. To improve safety, many agencies have turned to intersection conflict warning systems (ICWS). These systems, which give motorists real-time warnings about cross traffic, save lives at intersections that might not otherwise warrant more traditional traffic-control devices or geometric improvements.
The Minnesota Department of Transportation (MnDOT) was recently honored for its efforts in designing, testing, and helping deploy ICWS throughout Minnesota while leading a national effort to do more of the same throughout rural America. The White House named Sue Groth, MnDOT’s state traffic engineer and co-chair of the state’s Toward Zero Deaths program, as one of 12 people who are transportation “Champions of Change.” Groth was selected for work conducted by MnDOT and its partners to improve intersection safety.
“These champions represent the very best in American leadership, innovation, and progress,” said USDOT Secretary Ray LaHood at a May 8 ceremony.
A variety of ICWS have been developed and tested in many states over the past several years. Fourteen installations of varying designs are currently in place in Minnesota, including three sites with technology developed by the Intelligent Transportation Systems (ITS) Institute, a part of CTS, under funding from MnDOT and the USDOT. This technology—Cooperative Intersection Collision Avoidance System–Stop Sign Assist (CICAS–SSA)—warns drivers stopped on a secondary rural road when gaps in cross traffic on the highway are too small to cross safely or allow a turn.
No specific guidance has been available, however, for the many different types of intersections regarding placement, size, messaging, and so on—which means a fairly broad range of approaches are in use. MnDOT is a member of a Federal Highway Administration pooled-fund program that established an approach for more consistent deployment and further evaluation of ICWS. In addition to 15 states and other transportation agencies, several national standards groups and industry associations were engaged in this effort.
Moving forward, MnDOT is now launching a three-year Rural Intersection Conflict Warning System (RICWS) project that will deploy one type of system at a minimum of 20 and up to 50 additional intersections, says Jon Jackels, ITS program engineer with MnDOT.
The first of the new installations, in Carver County, will be evaluated by the ITS Institute. Led by research fellow Arvind Menon, researchers will use technology developed previously under the CICAS-SSA program to monitor the proposed RICWS and demonstrate its accuracy and reliability. They will then estimate the cost to reach the desired level of accuracy (99.95 percent of vehicles). RICWS costs vary significantly depending on factors such as the type of system, type of road, and location, Jackels says. Using the research findings, MnDOT will then proceed with the other 19 locations.
Jackels credits almost a decade of work with University researchers for helping build the foundation for the ICWS project. “That learning was really helpful to getting us where we are,” he says.
Many local partners are involved, Jackels notes, including Aitkin, Blue Earth, Carver, Kanabec, Kandiyohi, Lyon, Nicollet, Olmsted, Rice, St. Louis, and Wright Counties, as well as Edwards Township and the City of Glencoe.
Jackels anticipates more research may come out of this project. “Did RICWS make a difference? Did it change behavior at non-instrumented intersections? What impact did it have on the entire system?” The goal, he says, is to have complete standards for highway intersection design—and ultimately, safer roads.
“This is a winner because it’s going to save lives across the nation,” Jackels says.