Optimising total entry delay at roundabouts with unbalanced flow: a dynamic strategy for smart metering

• Published in: IET intelligent transport systems Vol. 13; no. 3; pp. 485 - 494
• Main Authors: Duan, Yuzhou, Qu, Xiaobo, Easa, Said, Yan, Yadan
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 01.03.2019
• Subjects: Delay reduction; different demand combinations; dynamic strategy; entry delays; entry traffic flow; light traffic; mathematical optimisation model; metering signal thresholds; metering signal‐based strategy; modern roundabouts; optimisation; Optimization; road traffic; road traffic control; road vehicles; roundabout; smart metering; Special Issue: Big Data Analytics and Artificial Intelligence (AI) Applications for Smart Transportation - Selected Papers from World Transportation Congress (WTC) 2018; total entry delay; Traffic control; traffic engineering computing; unbalanced flow patterns; metering signal thresholds; road traffic; dynamic strategy; road traffic control; smart metering; metering signal-based strategy; modern roundabouts; entry delays; traffic engineering computing; different demand combinations; total entry delay; optimisation; road vehicles; light traffic; delay reduction; unbalanced flow patterns; entry traffic flow; mathematical optimisation model; roundabout
• ISSN: 1751-956X; 1751-9578; 1751-9578
• DOI: 10.1049/iet-its.2018.5180

Modern roundabouts are widely used at intersections with light traffic, generally providing safety and other advantages. However, large entry delays are often observed at roundabouts with unbalanced flow patterns, even though the entry traffic flow is not high. A metering signal-based strategy is examined to mitigate the above problems. A mathematical optimisation model is formulated firstly with the objective of minimising the total entry delay, subject to the metering signal thresholds. Then a solution algorithm based on VISSIM simulation is developed. Finally, a case study is carried out to testify the feasibility and applicability of the proposed model. Extended scenarios analyses under different levels of approach volume, different demand combinations and different proportions of right-turn vehicles (left-side driving) are also conducted. Results show that the methodology can effectively improve the operational performance, and a delay reduction of up to 25.7% can be expected using the metering signal-based strategy. This can provide a criterion for the use of metering at the roundabout.