The Minnesota Department of Transportation (MnDOT) has over 1,000 two-way stop-controlled intersections on high-speed, multi-lane expressways across the state. These intersections have been found to have a higher incidence of fatal and serious injury crashes. Most of these crashes were right-angle related, typically associated with drivers attempting to cross all four lanes of the highway. Over the course of 10 years, these 1,000+ at-grade expressway intersections had 79 fatal crashes and 175 serious injury crashes.
Most of these intersections are characterized by high volumes on the state-owned trunk highway and low volumes on the typically locally-owned minor street that is stop controlled. Solutions such as traffic signals typically did not meet warrants, or often made the crash problem worse. Other solutions such as median closure are politically infeasible, and grade separated interchanges are often too expensive.
Minnesota researched and implemented the first J-turn intersection in the state in 2010 in Wilmar, MN. The intersection design works by preventing traffic on the minor street from crossing the highway directly. Instead, vehicles trying to cross or turn left first make a right turn, then travel a short distance to a designated U-turn location to complete the intended maneuver.
The Wilmar location saw a complete elimination of fatal and serious injury crashes from the time of its construction to the present. Following this success, MnDOT has begun an aggressive campaign to install more of the intersections across the state. The state now has over 80 of these intersections (or variations) installed on the Trunk Highway Network, with over 30 more planned and programmed over the next five years. MnDOT has evaluated these intersections for traffic safety performance numerous times, most recently in 2021. This found a 69 percent reduction in fatal and serious injury crashes.
Even with the traffic safety, engineering, and design successes of the J-turn, MnDOT has faced challenges with getting public acceptance. Communities often balk when first presented the J-turn concept. Based on this, MnDOT has worked with numerous agencies to develop public engagement tools to better work with local agencies and concerned residents to ensure that the community is more comfortable with the J-turn. These include a Public Engagement Social Media Toolkit, the “J-turn communications and community engagement playbook,” and various presentations and other reports demonstrating the safety benefits of the change.
In sum, MnDOT has identified a proven traffic safety solution that saves lives, and has taken key steps to ensure widespread deployment by researching the effectiveness of the treatment, planning where these intersections can be installed, providing funding opportunities to build more, engaging the public, and working with local and statewide media to raise awareness of the safety benefits of J-turn intersections.
Additional Information
Federal Highway Administration Associate Administrator for Safety Cheryl Walker describes Minnesota's J-Turn project in her remarks.
