This fall, the American Association of State Highway and Transportation Officials (AASHTO) will publish the sixth edition of A Policy on Geometric Design of Highways and Streets, commonly known as the “Green Book.” It provides guidance to highway engineers and designers on finding unique design solutions that meet the needs of highway users while maintaining environmental integrity.

This guide is available in print, as an online download, and as a Web-based publication. The terms and concepts in the Green Book have been designed to coordinate with those in AASHTO's Roadside Design Guide to create more cohesive roadway and street designs of roadways and streets.

For a look at technical updates made from the previous edition, click here.