Signal control method and performance evaluation of an improved displaced left-turn intersection design in unsaturated traffic conditions

ABSTRACT

This paper proposes an improved layout for the Displaced Left-turn (DLT) intersection by combining the conventional DLT intersection with protected left-turn phases, based on the safe-crossing requirements of pedestrians and non-motorized vehicles. The delay and stops are weighted to form an integrated performance index (PI) in a real-time vehicle-to-infrastructure communication environment. The PI models, pertaining to all vehicles in non-DLT lanes, DLT lanes and shared through-right lanes are established based on the improved DLT intersection in unsaturated traffic conditions. In addition, a dynamic optimized method of traffic signal timing parameters is constructed based on minimizing average PI per vehicle and considering the traffic signals’ coordination at the main intersection and left-turn crossovers. The operational performance of the optimized method is validated using data collected at an intersection in Harbin, China.

KEYWORDS:

• Improved DLT intersection
• integrated performance index
• signal timing parameters optimization
• utility analysis

Acknowledgement

The authors acknowledge the anonymous reviewers for their valuable comments and suggestions. The authors would also like to acknowledge the financial support from Science and Technology Innovation Talent Research Special Fund Project of Harbin (Nos. 2016RAQXJ079).

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Xiancai Jiang http://orcid.org/0000-0001-7703-4004

Additional information

Funding

This work was supported by the Science and Technology Innovation Talent Research Special Fund Project of Harbin [grant number 2016RAQXJ079].