PATH

In Automated Highway Systems (AHS), vehicles are equipped with automatic control systems to govern the accelerating, steering and braking functions in order to maintain an appropriate speed and spacing with respect to the surrounding vehicles. One concept of AHS suggests the implementation of vehicle platoons with small spacing between vehicles. With vehicles moving closely together in platoons, the hazards of "chain-reaction" collisions become a concern. The benefits of small delta-V need to be weighed against the number of collisions in such feared "chain-collision" scenarios. This...

This dissertation investigates various aspect of the design and testing of on-ramp metering control systems, including optimization-based control and microscopic freeway modeling. A new technique for generating optimal metering plans is developed. As with most predictive designs, the ramp metering rates are found as the solution to a nonlinear optimization problem. In contrast to previous designs, the new approach 1) produces a globally optimal solution to the nonlinear problem, 2) requires only to solve a single linear program, and 3) allows the enforcement of hard constraints on the on-...

Mobile radio communications systems are attracting more and more attention since they provide a means for users on the move to exchange information with other stationary or mobile stations. The capability of communication on the move can support many services and create lots of applications. For example, in the future Intelligent Vehicles Highway Systems (NHS), mobile communication technologies have enabled two important subsystems, namely Advanced Traffic Management and Information Systems (ATMIS) and Automatic Vehicular Control Systems (AVCS). The purpose of this research is to develop a...

This report studies the current development of functional requirements and interface standards for the public transit industry. It begins with a critical review of recent architecture efforts and their functional and interface requirements. It then describes the results of a survey of public transit vendors that was conducted to learn about the technical characteristics of products and vendor attitudes toward interface standards. Four case studies of recent technology applications in the San Francisco Bay Area are then described. These case studies reflect that factors such as market...