Scheduling, Communication and Control of Traffic Flow with Heterogeneous Vehicle Characteristics

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

This award is being made under the Exploratory Research on Engineering Transport Industries (ETI) Program solicitation. Advances in Information and communication technology offer significant potential to relieve pressures of highway and railway operation. A class of problems is considered where technological advances offer significant potential to increase the capacity of the systems and reduce congestion (and thereby loss of human life and properly, lost time, pollution levels and fuel cost) by safer and more efficient scheduling and control of the system. The common features are the concentration on the Longitudinal dynamics of the flow of traffic (on highways or railways), the need to coordinate a large number of individual control units, and the use of simulation models to assess the characteristics of the longitudinal dynamics and the affects of controls on efficiency, capacity and safety. Communication means best suited to support the resulting control architecture are also identified. Semi-automated or fully automated driving on multi-lane urban highway systems is one of the central issues in alleviating urban congestion. Considered is the system-wide lane assignment problem, whereby an Urban Highway System Control Center (UHSCC) assigns to each vehicle a lane of travel (in each section of the highway) so as to maximize highway capacity. Simple models show that maneuvers have a significant effect on capacity, and that their number should be kept at a minimum. Suitable algorithm are developed to assign lanes to vehicles depending on their trip itinerary, based on the assumption that trip itineraries are concentrated in the UHSCC so that this information, not available to individual drivers, can be used to resolve this system-wide control problem. The use of Arcs (in some or all vehicles) can also increase the capacity because the reaction curve of the AVCS does not increase the inter-vehicle distance in function of lane velocity, and will, theoretically, maintain a set distance between vehicles. The average reaction curve of the AVCS controlled vehicles is estimated through simulations and used in lane assignment algorithms to balance excess lane capacity and I the capacity of the highway. Trains equipped with Positive Train Control (PTC) equipment and electronically controlled pneumatic (ECP) brakes have e significant potential to increase railway capacity. The problem of articulated braking of freight trains is one of the important control problems in railway transportation in US where the predominant type of railway transport is freight transport over long distances using trains consisting of over a hundred cars and three to four engines. Braking characteristics determine the safe stopping distance and the capacity of a railway section. A significant opportunity for better prediction of stopping times, safer braking on long grades, on undulating terrain and/or curved terrain, and for coordinated use of brakes in emergency conditions, is now available with ECP brake systems because the brake on each unit can be controlled individually. Algorithms are developed to better understand and exploit these possibilities.