Signal timing optimisation with the contraflow left-turn lane design using the cell transmission model

Abstract

Contraflow left-turn lane (CLL) design has been increasingly applied in China to relieve traffic congestion at signalised intersections. Existing studies evaluate the impacts of the CLL design, optimise the length of the contraflow left-turn lane, and propose actuated signal control strategies with a fixed signal phase sequence. We set up constraints to ensure the safety of the generated signal timing plan, employ the cell transmission model (CTM) to capture urban traffic dynamics, and formulate the optimisation of the CLL design at intersections as a Mixed-Integer Linear Programming (MILP) model. Our model optimises the length of the contraflow lane, signal phase sequence, and green time duration considering traffic dynamics and spatial holding capacities of links. Numerical experiments are conducted with real traffic volume data collected in Shenzhen, China, which show that our approach reduces the delay by 9.63% and increases the capacity by 11.48% compared with the actuated CLL design.

Keywords:

• Contraflow left-turn lane
• unconventional intersection design
• cell transmission model
• traffic signal control

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This research is supported by the National Natural Science Foundation of China [Grant 71761137003] and Center for Data-centric Management in the Department of Industrial Engineering at Tsinghua University [2020001].