Two Stop-Line Method for Modern T-Shape Roundabout: Evaluation of Capacity and Optimal Signal Cycle

Jalil, Khurrum; Xia, Yuanqing; Zahid, Muhammad Noaman; Kamal, Abdus Samad

doi:10.1155/2022/7679496

Cited by 4 publications

(3 citation statements)

References 22 publications

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“…Furthermore, Martin [42] compared the capacity of a metering system with a queue detector at 50 m and unmetered roundabouts and discovered that using a metering system could result in a group of vehicles approaching the roundabout with a longer acceptable gap between them. On the other hand, some studies [13,19,23,38,[43][44][45][46] limited the optimal location of queue detectors in their studies.…”

Section: Literature Reviewmentioning

confidence: 99%

“…Meanwhile, the optimal location of the queue detector improved the performance of signalized roundabouts [25,26,41]. This finding is less highlighted in previous studies because most of the studies focus on the improvement of the performance of roundabouts by selecting the best scenario of the roundabout construction, the optimization of cycle length, the optimization of capacity, and choosing the optimization of different geometric elements at signalized roundabouts, and limited studies focus on the optimal location of queue detectors [13,19,23,[43][44][45][46][57][58][59][60].…”

Section: Significance Of the Studymentioning

confidence: 99%

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Modeling of Queue Detector Location at Signalized Roundabouts via VISSIM Micro-Simulation Software in Amman City, Jordan

Assolie,

Sukor,

Khliefat

et al. 2023

Sustainability

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The growing number of vehicles in Jordan has contributed to traffic congestion, particularly at roundabouts. Roundabouts deflect high volumes of traffic flow. To improve the performance of roundabouts, it is necessary to consider the impact of all components on traffic conditions, especially delay, queue length, and level of service (LOS), to reduce congestion and enhance efficiency and sustainability, etc. This study aims to (a) identify the optimal queue detector locations on all approaches at two selected roundabouts in Amman, Jordan, using micro-simulation (VISSIM) supported by programming (Python) software, and (b) validate the simulated models with the best LOS. Traffic and geometric data of roundabouts (Prince Faisal Bin al-Hussein, fifth; and Prince Rashid Bin Hassan, sixth roundabouts) were used for simulation purposes. The queue detector (across 15 distinct scenarios at various distances) and standard (base scenario, 50 m from the stop line) locations were assessed for optimal placement. The model validation was made based on all scenarios including signalized and non-signalized roundabouts. The best-case scenario for queue detector location was determined based on the highway capacity manual (HCM) criteria for measurement of effectiveness (MOE) at roundabouts. The optimal location was measured based on the duration of traffic delay (seconds), average queue length (m), and LOS. The optimal queue detector’s location was observed to be 97 m from the roundabout stop line. It can reduce the traffic delay (or speed up the traffic flow) by 85.25%. The average queue length can be reduced up to 76.76%. The LOS F status on the selected roundabouts can be improved to LOS D. Overall, the application of adaptive signal and queue detectors in appropriate locations at all roundabout approaches is crucial to improve imbalanced traffic flow while reducing delays.

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Section: Literature Reviewmentioning

confidence: 99%

Section: Significance Of the Studymentioning

confidence: 99%

Modeling of Queue Detector Location at Signalized Roundabouts via VISSIM Micro-Simulation Software in Amman City, Jordan

Assolie,

Sukor,

Khliefat

et al. 2023

Sustainability

View full text Add to dashboard Cite

show abstract

“…In general, indirect/part-time/partial control using a metering system can be used to shift from unbalanced traffic flows to balanced traffic flows [6]. If roundabouts are under saturation flow, direct/full controlled roundabouts are preferred to smooth vehicle movements [7]. In recent years, several studies have attempted to maximise roundabout capacity through design changes or by installing traffic signals [8][9][10].…”

Section: Introduction 11 Backgroundmentioning

confidence: 99%

Study of Full Controlled Green Time Roundabouts – An Intelligent Approach

Bae

Kim

2023

PROMTT

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When roundabouts face congestion problems, the transition to signalised roundabouts is considered a solution to the problem. The majority of studies have concentrated on how to calculate the optimal cycle length and signal timing to minimise congestion at roundabouts. To date, intelligence algorithms with multi-objectives such as queue length, number of stops, delay time, capacity and so on are widely used for calculating signal timing. Although roundabout congestion can be generated by the weaving zone reducing roundabout capacity, there have been minimal studies which take into account the density in the weaving zone. This study proposed a hybrid gravitational search algorithm – ABFO random forest regression with the following objectives: density, delay time and capacity to find the optimal cycle length and green time in each phase of Changwon city hall roundabout in South Korea as a case study. The optimal cycle length and green time were calculated in MATLAB and microscopic simulation VISSIM sought the effectiveness of a signalised roundabout. The result of the analysis demonstrated that signalised roundabouts with 102 seconds cycle length (phase 1 – 65 seconds of green time and phase 2 – 37 seconds of green time) can reduce density by 46.1%, delays by 32.8% and increase roundabout capacity by 14.8%.

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A Speed Optimization Strategy for Smooth Merging of Connected and Automated Vehicles at T-Shape Roundabout

et al. 2022

Self Cite

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This paper presents a novel holistic T-shape roundabout coordination system (TCS) that addresses the connected and automated vehicles (CAVs) flow in a typically isolated T-shape roundabout. The TCS optimizes the states of each approaching vehicle in a receding horizon control framework that aims to minimize the total crossing time, considering the vehicles' dynamic states. The control method ensures the comfortable crossing of each vehicle by retaining the basic features of a traditional traffic control management system. The optimal states are broadcasted ahead by TCS, which enables the CAVs to form a cluster and tune their speed in order to cross the roundabout with minimum stop-delay. We evaluate the effectiveness of the proposed TCS method under the various traffic flow demand. From the executed simulation, it is observed that the optimization process usually improves the average velocity, and reduces both the traffic density and vehicles' idling situation. As a consequence, the fuel consumption of each vehicle around the roundabout is also decreased. These outputs are compared with the traditional method, showing that the overall flow performance significantly improves in the case of the proposed scheme, and vehicles have rapid optimization for a smooth crossing.INDEX TERMS bi-level coordination, CAVs clustering, connected and automated vehicles, optimization, receding horizon control, T-roundabout,

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Two Stop-Line Method for Modern T-Shape Roundabout: Evaluation of Capacity and Optimal Signal Cycle

Cited by 4 publications

References 22 publications

Modeling of Queue Detector Location at Signalized Roundabouts via VISSIM Micro-Simulation Software in Amman City, Jordan

Modeling of Queue Detector Location at Signalized Roundabouts via VISSIM Micro-Simulation Software in Amman City, Jordan

Study of Full Controlled Green Time Roundabouts – An Intelligent Approach

A Speed Optimization Strategy for Smooth Merging of Connected and Automated Vehicles at T-Shape Roundabout

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