This report provides interim results on the design of interfaces between automated highways and conventional street systems. The purpose here is to identify the strategic issues in interface design, and to provide preliminary analysis on just one of these issues (separation between highway entrance and exits). Future research will explore a full set of strategic issues in greater depth. The central concept explored in this report is how to design a roadway system that comprises multiple layers, some of which are designed for the purpose of accessibility, and others of which are designed more for the purpose of speed and capacity. With multiple layers, efficient functioning of the roadway system depends on creating effective roadway interfaces. The interface between an automated highway system and conventional roadways presents new challenges for interface designed, which are explored in this paper.

This report models response times and delays for highway incidents, according for spacing between interchanges and the time penalty for changing directions, enabling a response vehicle to reach an incident on the opposite side of the highway. A fundamental question in dispatching incident crews is whether to send the closest vehicle that is currently available or to wait for another to become available that is even closer. Waiting for a closer one is advantageous because service time is effectively reduced, adding to capacity and providing stability at higher levels of utilization. But waiting for a vehicle to become available adds uncertainty, which contributes to expected traffic delay. As a consequence, any reasonably robust dispatch strategy must provide for a hybridization of the two objectives, trading off greater certainty in response time against stability at higher utilization levels.

In 1996, the Federal Highway Administration completed a program to develop a national system architecture (NSA) for intelligent-transportation-systems. This report presents recommendations on methodologies by which system architecture can be used to improve the deployment of transportation management projects, with emphasis on multi-jurisdictional projects. The report is part of a larger project addressing the deployment of an ITS system architecture in California. The project as a whole is led by Claremont Graduate School, and is documented in a separate report.

This working paper examines the process for managing incidents on highways, as it is applied in Los Angeles County. The examination is based on interviews with various agencies, including law enforcement, state highway department, coroners office, and LA County MTA Freeway Service Patrol, along with direct observation through ride-alongs. Follow-up work will quantify the benefits of improved incident management, through analysis of freeway performance and response characteristics during incidents.

This report documents the institutional issues that have faced the Orange County probe project, a multi-agency project designed to equip a fleet of buses with Global Positioning System (GPS) based tracking equipment and to use tracking data for multiple purposes. The usefulness of the data involve: 1) bus schedule adherence and fleet management; 2) collection of information on roadway traffic congestion; and, 3) dissemination of transit data to patrons.

This paper demonstrates how the constraints of overnight delivery affect the design of pickup and delivery systems. Cost depends on the number of vehicle routes needed to pickup and deliver shipments. This number in turn depends on the critical parts of the driver's day: the morning delivery period, up to the delivery deadline, and the afternoon pickup period, after the cutoff time. Pickup routing is the more complicated, due to the dynamic nature of customer calls. Models are developed to assess the workload remaining to be completed at the cutoff time and, from this value, the number of routes required to pick up the shipments.

Local area freight networks (LANs) are used to collect and distribute freight within metropolitan regions. Focusing on common carriers, this paper classifies LAN topologies, then shows how the optimal topology depends on demand characteristics. Continuous space approximations are used to analyze topologies as well as to analyze the relationship between cost and number of terminals. Key findings are summarized in Table 1.

This paper focuses on the role of standardization in managing and controlling an intelligent transportation system (ITS). The authors review activities and processes used by standards setting organizations. It is determined that standards address the needs for defining common interfaces for communication with field devices and communication between Transportation Management Centers (TMCs). The authors conclude, however, that standardization has not addressed the need to develop protocols and procedures for responding to transportation events and managing the transportation system.