Rural Intersection Crashes: Identifying Intersections for Intersection Decision Support

In Minnesota, over 60% of fatal intersection crashes occur at rural intersections. Older and younger drivers are over-represented in these fatalities. Analyses of crashes indicate that a large number of crashes at rural unsignalized intersections are due to the driver’s inability to correctly pick a safe lag for entering the traffic stream. Moreover, many other states exhibit similar rural intersection crash and fatality rates and characteristics. The American Association of State Highway and Transportation Officials (AASHTO) identified design and operational improvements of highway intersections as one of the twenty-two key emphasis areas in their Strategic Highway Safety Plan (SHSP). Development and use of new technologies at high-priority intersections was identified in the SHSP as an initiative to address intersection crashes. However, not all rural intersections suffer from high crash rates. With limited public funding available for highway safety improvements, it is imperative to initially apply safety technology in locations where the benefit: cost ratio is maximized. As the cost to deploy drops over time, because of the economy of scale, intersections with less severe safety problems can be equipped with the advanced technology. Described herein is a methodology used (or to be used) in nine U.S. states to identify candidate rural intersections which exhibit both higher than expected crash rates and crash characteristics which are expected to be correctable with emerging technologies. Key findings include the methodology to identify problematic intersections using state or local crash record databases, validation that the key problem with these rural intersections is poor lag selection, and a list of intersections in each state where it is expected that emerging technology can improve rural intersection safety. The method described herein can be replicated in other states which suffer from rural highway intersection crashes.