In the last 10 or more years, a significant portfolio of research related to the geometric design of highways and streets has been completed (and many other projects currently in process) through NCHRP that has had a direct, meaningful, and noteworthy impact on the geometric design practice in the United States.  However, the determination of the research needs and topics were not done haphazardly; rather, there was a strategic agenda published by Transportation Research Circular E-C110: Geometric Design Strategic Research (2007) that served to prioritize and inform the research program.  This strategic agenda was informed through previous NCHRP synthesis efforts – initially through NCHRP Synthesis 299: Recent Geometric Design Research for Improved Safety and Operations (2001) and then updated with NCHRP Synthesis 432: Recent Roadway Geometric Design Research for Improved Safety and Operations (2012) – and in a cooperative manner between the AASHTO and TRB committees.

The objective of this project is to inform the long-range pipeline of research needed to maintain the AASHTO’s A Policy on Geometric Design of Highways and Streets (the Green Book) as the primary and authoritative source of guidance and information concerning the practice of highway, road, and street design in the United States.