This paper presents a theory for automated traffic flow, based on abstraction of vehicle activities such as entry, exit and cruising, derived from a vehicle's automatic control laws. The theory formulates TMC traffic plans as the specification of the activities and speed of vehicles, and the entry and exit flows for each highway section. The theory permits the study of transient phenomena such as congestion, and TMC feed back traffic rules designed to deal with transients.

In this study, the authors propose a hierarchical control architecture for dealing with faults and adverse environmental conditions on an Automated Highway System (AHS). The faults are classified according to the capabilities remaining on the vehicle or roadside after the fault has occurred. Information about these capabilities is used by supervisors in each of the layers to select appropriate control strategies. The extended control strategies that are needed by these supervisors in each layer of the hierarchy are outlined. A companion paper, abstracted in PATH Database record no. 9597, develops and verifies protocols for extended coordination strategies and maneuvers.