Due to growing acceptance, an increasing number of new Alternative Intersections and Interchanges (AIIs) are being built in the United States. AII designs may involve reversing traffic lanes from their traditional directions, which could introduce confusion and create safety issues for pedestrians and bicyclists. In some cases, pedestrian paths and bicycle facilities cross through islands or take different routes than expected. Little information existed on how to quantitively identify and remediate these challenges.
Kittelson partnered with the Institute for Transportation Research and Education to lead research into the development of a guide for transportation practitioners to improve and integrate non-motorized user safety considerations at alternative intersections and interchanges through planning, design, and operational treatments. This included developing a quantitative planning-level alternatives analysis for non-motorized users that can be used on all intersection types.
Kittelson’s research team identified and evaluated current practices, conducted user focus groups, and developed recommended design alternatives. A national team of alternative intersection, interchange, and pedestrian/bicycle transportation experts supported the research activities.
NCHRP 07-25: Pedestrian and Bicycle Safety at Alternative Intersections and Interchanges
This research project led to the development of methods for ensuring pedestrian and bicycle safety at AIIs. The resulting guidebook provides transportation practitioners with ways to integrate non-motorized user-safety considerations at AIIs through planning, design, and operational treatments. Also included in the guide are best practices for quantitatively conducting an alternatives analysis of intersection designs. This includes identifying and ranking treatments for typical types of projects, measuring each treatment’s effectiveness, and evaluating their safety and operational outcomes.