Alternative Intersections and Interchanges (A.I.I.s) are designs that improve operations and safety for motorized traffic by strategically adjusting the geometric features at a given location, working on the general principle of redistributing motor vehicle demand at an intersection in an attempt to limit the need to add capacity with new lanes to improve traffic flow. The TRB National Cooperative Highway Research Program's NCHRP Research Report 948: Guide for Pedestrian and Bicyclist Safety at Alternative and Other Intersections and Interchanges provides specific guidance for four common A.I.I.s: Diverging Diamond Interchange (DDI), Restricted Crossing U-Turn (RCUT), Median U-Turn (MUT), and Displaced Left-Turn (DLT). 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, bicyclists, and pedestrians as well as better accommodations for pedestrians and bicyclists, including pedestrians with disabilities.

Intersections are challenging locations for all road users, but they can be especially difficult for people walking and biking. Between 2014 and 2016, 27 percent of pedestrians and 38 percent of bicyclists killed in crashes were struck at intersections. The TRB National Cooperative Highway Research Program's NCHRP Research Report 926: Guidance to Improve Pedestrian and Bicyclist Safety at Intersections provides a succinct process for selecting intersection designs and operational treatments that provide safety benefits for pedestrians and bicyclists, and the most appropriate situation for their application. In 2016 and 2017, pedestrians and bicyclists made up 18 percent of all fatalities on U.S. streets, despite representing less than 4 percent of all trips. This continues an upward trend in these modes' share of roadway fatalities since 2007.

This report presents an overview of principles and practices that will help readers develop intersection designs that achieve the highest levels of safety, mobility and cost-effectiveness. It demonstrates practical design measures and tools that will improve intersection safety, provides examples of effective applications, and discusses experiences with innovative solutions.

NACTO's Urban Bikeway Design Guide quickly emerged as the preeminent resource for designing safe, protected bikeways in cities across the United States. It has been completely re-designed with an even more accessible layout. The Guide offers updated graphic profiles for all of its bicycle facilities, a subsection on bicycle boulevard planning and design, and a survey of materials used for green color in bikeways. The Guide continues to build upon the fast-changing state of the practice at the local level. It responds to and accelerates innovative street design and practice around the nation.