The New AASHTO Metric Policy on Geometric Design of Highways and Streets

摘要

In 1992 The American Association of State Highway and Transportation Officials (AASHTO) began the process of converting A Policy on Geometric Design of Highways and Streets (popularly known as the "Green Book") to the metric system. This conversion was necessitated by the need to comply with a federal law requiring that each federal government agency begin using, with few exceptions, the International System of units (SI) in all procurements, grants and other business-related activities.