Traffic Signal Optimization Models Minimizing Vehicles’ Average Delay in an Isolated Signalized Intersection

Abstract

Traffic lights play main role nowadays in urban traffic. One effective way to solve congestion is to adjust traffic signal timings, especially when the infrastructure investments are limited. This research developed two nonlinear objective optimization models that minimize the average traffic delay in isolated signalized intersection with several constraints, with a precondition that the degree of saturation must be under 0.9. Microscopic simulations are performed to simulate an isolated signalized intersection according to the traffic signal timing calculated by the developed models. Verification of the developed nonlinear objective optimization models is performed based on the simulation results. The simulation results show a 27% decrease of the average loss time and 24% decrease of the average waiting time for all vehicles if apply the signal timing calculated by the second developed model, compared with the simulation results of the fixed signal timing calculation method recommended in Japan from 2018.