Peak period control of a freeway system some theoretical investigations.

This paper contains a series of theoretical considerations pertaining to the control of a freeway system during peak traffic periods.It attempts to answer such questions as the following: What are the objectives of operation of a highway system? What type of control technique should be used? What type of traffic detection is required? Where is it to be located? How should the entire freeway system be considered and controlled to produce optimal operation? An arbitrary street and/or freeway system is analysed to determine the objective function of goal of operation for the system. An input-output analysis is used. A theory of flow at bottlenecks is developed to explain the reduction of flow rate at some bottlenecks during congestion while the flow rate at other bottlenecks remains at is capacity level during congestion. This is a macroscopic flow model based on basic continuity equations. Other macroscopic models of traffic behaviour at and upstream of a bottleneck are to determine what traffic variables are to be detected to a product congestion and (b) indicate congestion and how for from the critical sections the detection must be made in order to allow control decisions to be made. Several criteria are established for control techniques and several control techniques are established for control techniques and several control techniques are established for control techniques and several control techniques are examined in light of these criteria. The possible role of each in a final control system is also discussed. Finally, a linear programming model of the operation of a freeway system is presented. This can be used as a descriptive model, but with some modifications could probably be used to provide the control actions required for optimal system operation. Interpretation of the dual variables and a sensitivity analysis are included and these provide many valuable insights into the operation of a freeway system. The linear programming approach suggested a method of determining demand at a certain freeway location.