Integrated Optimization Model of Lane Function and Signal Control for Tandem Intersections

Abstract

This paper presents an integrated optimal controller for the tandem intersection with lane function design and signal control, aiming to improve intersection efficiency and service reliability with a multi-objective formulation. The tandem intersection is a type of unconventional intersection that can re-organize the vehicles at entrance lanes with sorting areas, and improve intersection capacity through the coordination of pre-signals and main signals. However, most existing studies related to tandem intersection control assume that the lane functions in the sorting areas for both the through and left-turn movements are the same, and the traffic demand remains static. To fill these gaps, this paper first identifies six different tandem control modes based on the different lane functions and phase sequence schemes in the sorting area, and the corresponding delay models for each mode are derived. Furthermore, an integrated optimization model is developed to minimize the mean and semistandard deviation of the intersection delay, and the Non-dominated Sorting Genetic Algorithm-II is used to obtain the optimal solution. A case study is conducted in a real-world intersection in Melbourne, Australia, under various traffic conditions. The results show that the proposed method can decrease average delay and queue length by 19.61% and 20.94%, respectively, compared with conventional intersection design.