Document Type


Publication Date

July 1994

Publication Title

PATH Research Report


AHS, Traffic Planning, Functional Architecture, Traffic Simulation


Industrial Engineering | Operations Research, Systems Engineering and Industrial Engineering | Systems Engineering


In a fully automated Automated Highway System (AHS), the roadside control system and the vehicles themselves are responsible for moving the large number of vehicles safely and efficiently. Therefore, the task of operating an AHS is drastically different from and much more complex than its conventional counterpart. Resulting from a large number of design options, there exist many possible ways to operate an AHS. Each of these possible operating scenarios will support a different set of functions. A crucial task in AHS R&D is to evaluate and compare these potentially large number of different AHS operating scenarios with respect to the achievable capacity.To enable simulation of various operating strategies without requiring massive program modification or database change, a flexible software structure and robust database design are required. This in turn necessitates a robust AHS functional architecture that guides the development and evolution of the required simulation tools. This paper identifies major traffic planning functions useful for optimizing the capacity of one or more major AHS operating scenarios and organizes them in a robust architecture that is modular, hierarchical, complete, expandable and integratable.


This work was performed as part of the California PATH Program of the University of California, in cooperation with the State of California Business, Transportation, and Housing Agency, Department of Transportation; and the United States Department Transportation, Federal Highway Administration.The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the State of California. This report does not constitute a standard, specification, or regulation.This report is also available at this link.