Barriers to Implementation of Unconventional Intersection Designs: A Survey of Transportation Professionals

Numerous unconventional intersection and interchange designs (UIIDs) exist with documented benefits, but implementation is slow. There are public, professional, and political barriers. Numerous papers explain the benefits of one design or compare designs, but few identify common barriers. This research surveyed transportation professionals to identify the barriers inhibiting the implementation of promising UIIDs and to identify solutions. Engineers believe that the public’s main concerns are driver confusion and fear of the unknown. Survey results highlight education as important, and that public opinion generally improves once an UIID is constructed. Professionals and politicians want proof that a design will work and are reluctant to try nonstandard designs. An important political consideration is cost, but the life cycle cost can be competitive. We need guidelines to assist designers, increased focus on alternatives analysis, and inclusion of UIIDs in planning. This will make the designs more familiar to the public and decrease opposition.