Guide for Pedestrian and Bicycle Safety at Alternative Intersections and Interchanges (AII)

Announcement $400,000

New alternative intersection and interchange designs – including Diverging Diamond Interchanges (DDI), Displaced Left-Turn (DLT) or Continuous Flow Intersections (CFI), Restricted Crossing U-Turn (RCUT) intersections, Median U-Turn (MUT) intersections, Quadrant Roadway (QR) intersections – are being built in the United States. These designs may involve reversing traffic lanes from their traditional directions, which may introduce confusion and create safety issues for pedestrians and bicyclists. In addition, pedestrian paths and bicycle facilities may cross through islands or take different routes than expected. These new designs are likely to require additional information for drivers, cyclists, and pedestrians as well as better accommodations for pedestrians and bicyclists, including pedestrians with disabilities.
 
A central concern with alternative intersections is how to provide information to pedestrians, bicyclists, and drivers about the direction of car traffic, pedestrian crossing, and bicycle facilities particularly when those new intersection designs feature unfamiliar traffic flows and patterns. The concern is acute for visually impaired pedestrians, who require information about the alignment of crosswalks, signal controls, crossing times, direction of traffic, and direction through islands. Consistency in how information is provided is important as well; for example, various types of paths and lane markings are being used for bicyclists, with little information about the advantages and disadvantages of different strategies.