Traffic signal optimization for emissions mitigation in urban road networks with contraflow left‐turn lanes

The concept of contraflow left‐turn lane (CLL) design has been proposed for nearly 10 years, which provides a novel approach to alleviate traffic congestion in urban areas, especially for those signalized intersections with heavy left‐turn traffic. While putting forward the practical application of CLL design to area‐wide signalized intersections, whether the control scheme of large‐scale signalized intersections with CLLs could be more sustainable remains an open question. This paper analyzes spatiotemporal characteristics of the CLL system and proposes analytical traffic and emission models based on the finite capacity queuing model, in which the special queuing behavior brought by the pre‐signal is explicitly considered. A sustainable traffic signal control framework is built to optimize signal timings of intersections with CLLs. A real‐world case study based on a road network in Yangon is conducted, and the results illustrate the proposed method's efficiency and sustainability in managing signalized intersections with CLLs in road networks.