Abstract
This is the second in a series of interim reports that are being prepared in connection with the development of a Companion Guidebook to the American Association of State Highway and Transportation Officials (AASHTO) publication "A policy on geometric design of highways and streets". Commonly referred to as the AASHTO "Green Book", this document provides guidance to designers who are responsible for the preparation of the preliminary and final design plans for all types of roads (new, reconstructed, or restored).