The document is a policy formulated by AASHTO and the Federal Highway Administration, which should be followed when designing highways and roads.
The Roadway Design Manual Part I establishes the policy framework for geometric design of highways and streets. It mandates adherence to the 2011 AASHTO "Green Book" and specific state-approved Interstate System design standards for federal-aid projects.
The manual details the selection of project design criteria, emphasizing functional classification, design speed, traffic volumes, and terrain. It provides minimum design speeds for various road types, including local rural roads, collectors, arterials, and freeways, based on terrain conditions such as level, rolling, or mountainous.
The adoption of the policy, "A Policy on Geometric Design of Highways and Streets" (2011) by AASHTO and the Federal Highway Administration will supersede all of the previous AASHTO policies.
It is the responsibility of the Section Engineers and Project Engineers to be assured that all plans, specifications, and estimates conform to the design criteria.
The functional classification groups streets into Interstate, Freeway, Arterial (including expressways), Collector, and Local.