An approach to optimize the settings of actuated signals

Abstract

Traffic-actuated signal employs relatively complex control logic to regulate traffic flow. Introduction of control variables into the traffic-actuated system contributes to system operational flexibility and complexity, and also complicates the system with uncertainties. The paper proposes two tentative methods to optimize the actuated signal parameters: basic requirements of controller parameters and analytical model, and macroscopic computer simulation. It is concluded that when the actuated signal operates within the volume/capacity range of 0.4 to 0.6, it will create the most significant benefits; the research suggests that minimum green time in the main street shall be set long enough to meet the required demand, preferably at the 60% of the main street capacity. In order to ensure less control delay in a semi-actuated intersection, relatively small values of vehicle extension (e.g., 2.5 s) and maximum green time are recommended to be assigned to the less important street.