Rural multi-lane divided highways are generally characterized by higher posted travel speeds and lower density of intersections (which are typically two-way stop controlled). The combination of multiple lanes of high speed traffic, the at-grade access, and driver performance often leads to severe right angle collisions. At-grade intersections along multi-lane roadways present challenging conditions for drivers in terms of judging gaps between high-speed traffic from two different directions separated by a median. Some states have begun to address rural high speed intersection crashes through physically restricting crossing movements (left and thru) which simplifies driver decision making in terms of gap acceptance. These treatments are referred to in Minnesota (a midwestern state in the US) as Reduced Conflict Intersections (RCI). Terms used by other agencies include: Restricted Crossing U-turn (RCUT) and J-Turn. In this paper, we will use the terminology RCI.

An RCI restricts minor road vehicles from making left or through movements. Instead, these vehicles make a right turn and travel a short distance downstream on the major road and then execute a U-turn. Drivers intending to turn left then continue on the expressway and drivers who intended to cross the intersection, then make a right turn. Major road vehicles are prevented from making a left turn. They continue straight to the U-turn location and after executing that movement, turn right at the intended minor street approach. Right turning vehicles in all cases are unaffected.

The main objective of this study was to evaluate large vehicle operational behavior at an RCI compared to traditional non-RCI intersection. Large truck behavior was videotaped and metrics such as exposure time, queuing time, travel time, and conflicts extracted and compared at RCI and control intersections.