scholarly journals Bi-Level Coordinated Merging of Connected and Automated Vehicles at Roundabouts

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6533
Author(s):  
A. S. M. Bakibillah ◽  
Md Abdus Samad Kamal ◽  
Chee Pin Tan ◽  
Susilawati Susilawati ◽  
Tomohisa Hayakawa ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Traffic Flow ◽  
Traffic Congestion ◽  
Cooperative Control ◽  
Optimization Problem ◽  
Traffic Flows ◽  
Automated Vehicles ◽  
Average Travel Time ◽  
Travel Delay ◽  
Velocity Average

Traditional uncoordinated traffic flows in a roundabout can lead to severe traffic congestion, travel delay, and the increased fuel consumption of vehicles. An interesting way to mitigate this would be through cooperative control of connected and automated vehicles (CAVs). In this paper, we propose a novel solution, which is a roundabout control system (RCS), for CAVs to attain smooth and safe traffic flows. The RCS is essentially a bi-level framework, consisting of higher and lower levels of control, where in the higher level, vehicles in the entry lane approaching the roundabout will be made to form clusters based on traffic flow volume, and in the lower level, the vehicles’ optimal sequences and roundabout merging times are calculated by solving a combinatorial optimization problem using a receding horizon control (RHC) approach. The proposed RCS aims to minimize the total time taken for all approaching vehicles to enter the roundabout, whilst minimally affecting the movement of circulating vehicles. Our developed strategy ensures fast optimization, and can be implemented in real-time. Using microscopic simulations, we demonstrate the effectiveness of the RCS, and compare it to the current traditional roundabout system (TRS) for various traffic flow scenarios. From the results, we can conclude that the proposed RCS produces significant improvement in traffic flow performance, in particular for the average velocity, average fuel consumption, and average travel time in the roundabout.

Dynamic route guidance strategy in a two-route pedestrian-vehicle mixed traffic flow system

2016 ◽  
Vol 27 (09) ◽  
pp. 1650099 ◽  
Author(s):  
Mianfang Liu ◽  
Shengwu Xiong ◽  
Bixiang Li
Keyword(s):  
Traffic Flow ◽  
Traffic Congestion ◽  
Rapid Development ◽  
System Stability ◽  
Mixed Traffic ◽  
Traffic Flows ◽  
Feedback Strategy ◽  
Threshold Control ◽  
Mixed Traffic Flow ◽  
System Equilibrium

With the rapid development of transportation, traffic questions have become the major issue for social, economic and environmental aspects. Especially, during serious emergencies, it is very important to alleviate road traffic congestion and improve the efficiency of evacuation to reduce casualties, and addressing these problems has been a major task for the agencies responsible in recent decades. Advanced road guidance strategies have been developed for homogeneous traffic flows, or to reduce traffic congestion and enhance the road capacity in a symmetric two-route scenario. However, feedback strategies have rarely been considered for pedestrian-vehicle mixed traffic flows with variable velocities and sizes in an asymmetric multi-route traffic system, which is a common phenomenon in many developing countries. In this study, we propose a weighted road occupancy feedback strategy (WROFS) for pedestrian-vehicle mixed traffic flows, which considers the system equilibrium to ease traffic congestion. In order to more realistic simulating the behavior of mixed traffic objects, the paper adopted a refined and dynamic cellular automaton model (RDPV_CA model) as the update mechanism for pedestrian-vehicle mixed traffic flow. Moreover, a bounded rational threshold control was introduced into the feedback strategy to avoid some negative effect of delayed information and reduce. Based on comparisons with the two previously proposed strategies, the simulation results obtained in a pedestrian-vehicle traffic flow scenario demonstrated that the proposed strategy with a bounded rational threshold was more effective and system equilibrium, system stability were reached.

An Overview of Lane Changing Model at Signalised Intersection

2016 ◽  
Vol 13 (2) ◽  
pp. 39
Author(s):  
Jezan Md Diah ◽  
Li Sian Tey ◽  
Fathiyah Roslee
Keyword(s):  
Traffic Flow ◽  
Traffic Engineering ◽  
Traffic Congestion ◽  
High Potential ◽  
Traffic Flows ◽  
Crucial Issue ◽  
Lane Changing ◽  
Intersection Model ◽  
The Right ◽  
Signalised Intersection

In recent years, lane changing has become a crucial issue in traffic engineering and safety aspect due to distribution of vehicles across lanes thus contributing to traffic movements. In order to keep the right route, drivers have to change their lanes. However, lane changing has a high potential of accidents, especially at signalised intersection. This may cause the traffic flow to become heavier and traffic congestion. The aims of this study are to study on lane changing issue at signalised intersection, to determine the factors contributing to lane changing at signalised intersection and to develop a model for improvement of traffic flow in lane changing behaviour at signalised intersection. Lane changing model is important because it will reduce traffic congestion and smoothen the traffic. This study will contribute in studying the changing lane issue at signalised intersection which is to control the flow of traffic in order to ensure the traffic flows smoothly and to reduce traffic congestion especially on the merging issue at signalised intersection. Keywords: lane changing, signalised intersection, model, traffic flow

scholarly journals Cooperative U-Turn Merging Behaviors and Their Impacts on Road Traffic in CVIS Environment

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Wenjing Wu ◽  
Renchao Sun ◽  
Yongxing Li ◽  
Runchao Chen
Keyword(s):  
Traffic Flow ◽  
Traffic Congestion ◽  
Cooperative Control ◽  
Control Algorithm ◽  
Road Traffic ◽  
Control Strategies ◽  
Arrival Rate ◽  
Urban Traffic ◽  
Delay Minimization ◽  
Infrastructure System

U-turn behavior of vehicle is one of the main causes of urban traffic congestion and accidents. A collaborative U-turn merging control algorithm is studied with collision avoidance and delay minimization for vehicles under Cooperative Vehicle Infrastructure System (CVIS) environment. Two control strategies, zip merging and platoon merging control, are proposed. The applicability of these two strategies is compared from the perspective of efficiency and driving comfort. The cellular automaton simulation system composed of a two-way four-lane traffic flow with a U-turn facility in middle of road is established with cooperative control algorithm imbedded. The influence of cooperative U-turn merging behaviors on traffic performance is evaluated by analyzing the arrival rates of main lane and U-turn vehicles and their relationship between one another. The simulation results show that the arrival rate of vehicles on target lane has a great impact on traffic delay. The cooperative control can improve the traffic flow only in the condition that the arrival rate of vehicles on target lane is less than 0.7. It provides some practical references for transportation agencies to meet efficiency requirements of the U-turn section when they apply cooperative control strategy.

scholarly journals Integrated Variable Speed Limits Control and Ramp Metering for Bottleneck Regions on Freeway

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Ming-hui Ma ◽  
Qing-fang Yang ◽  
Shi-dong Liang ◽  
Zhi-lin Li
Keyword(s):  
Traffic Flow ◽  
Traffic Congestion ◽  
Ramp Metering ◽  
Variable Speed ◽  
Speed Limits ◽  
Advanced Control ◽  
Variable Speed Limits ◽  
Travel Delay ◽  
Freeway Bottleneck

To enhance the efficiency of the existing freeway system and therefore to mitigate traffic congestion and related problems on the freeway mainline lane-drop bottleneck region, the advanced strategy for bottleneck control is essential. This paper proposes a method that integrates variable speed limits and ramp metering for freeway bottleneck region control to relieve the chaos in bottleneck region. To this end, based on the analyses of spatial-temporal patterns of traffic flow, a macroscopic traffic flow model is extended to describe the traffic flow operating characteristic by considering the impacts of variable speed limits in mainstream bottleneck region. In addition, to achieve the goal of balancing the priority of the vehicles on mainline and on-ramp, increasing capacity, and reducing travel delay on bottleneck region, an improved control model, as well as an advanced control strategy that integrates variable speed limits and ramp metering, is developed. The proposed method is tested in simulation for a real freeway infrastructure feed and calibrates real traffic variables. The results demonstrate that the proposed method can substantially improve the traffic flow efficiency of mainline and on-ramp and enhance the quality of traffic flow at the investigated freeway mainline bottleneck.

Smart Driving System for Improving Traffic Flow

2017 ◽  
Vol 7 (7) ◽  
pp. 236
Author(s):  
Rajesh Kumar Gupta ◽  
L. N. Padhy ◽  
Sanjay Kumar Padhi
Keyword(s):  
Traffic Flow ◽  
Traffic Congestion ◽  
Urban Areas ◽  
Adaptive Cruise Control ◽  
Human Perception ◽  
Cruise Control ◽  
Driving System ◽  
V2v Communication ◽  
Traffic Conditions ◽  
Cooperative Adaptive Cruise Control

Traffic congestion on road networks is one of the most significant problems that is faced in almost all urban areas. Driving under traffic congestion compels frequent idling, acceleration, and braking, which increase energy consumption and wear and tear on vehicles. By efficiently maneuvering vehicles, traffic flow can be improved. An Adaptive Cruise Control (ACC) system in a car automatically detects its leading vehicle and adjusts the headway by using both the throttle and the brake. Conventional ACC systems are not suitable in congested traffic conditions due to their response delay.  For this purpose, development of smart technologies that contribute to improved traffic flow, throughput and safety is needed. In today’s traffic, to achieve the safe inter-vehicle distance, improve safety, avoid congestion and the limited human perception of traffic conditions and human reaction characteristics constrains should be analyzed. In addition, erroneous human driving conditions may generate shockwaves in addition which causes traffic flow instabilities. In this paper to achieve inter-vehicle distance and improved throughput, we consider Cooperative Adaptive Cruise Control (CACC) system. CACC is then implemented in Smart Driving System. For better Performance, wireless communication is used to exchange Information of individual vehicle. By introducing vehicle to vehicle (V2V) communication and vehicle to roadside infrastructure (V2R) communications, the vehicle gets information not only from its previous and following vehicle but also from the vehicles in front of the previous Vehicle and following vehicle. This enables a vehicle to follow its predecessor at a closer distance under tighter control.

Traffic Flow Management Impact on Delay and Fuel Consumption: an Atlanta Case Study

2012 ◽  
Vol 20 (3) ◽  
pp. 203-224 ◽  
Author(s):  
Shon R. Grabbe ◽  
Banavar Sridhar ◽  
Avijit Mukherjee ◽  
Alexander Morando
Keyword(s):  
Fuel Consumption ◽  
Traffic Flow ◽  
Flow Management ◽  
Traffic Flow Management

scholarly journals Formation of the Traffic Flow Rate under the Influence of Traffic Flow Concentration in Time at Controlled Intersections in Tyumen, Russian Federation

2021 ◽  
Vol 13 (15) ◽  
pp. 8324
Author(s):  
Viacheslav Morozov ◽  
Sergei Iarkov
Keyword(s):  
Traffic Flow ◽  
Flow Rate ◽  
Traffic Congestion ◽  
Traffic Management ◽  
System Analysis ◽  
Motor Vehicle ◽  
Experimental Studies ◽  
Transport Systems ◽  
Experiment Planning ◽  
Traffic Light

Present experience shows that it is impossible to solve the problem of traffic congestion without intelligent transport systems. Traffic management in many cities uses the data of detectors installed at controlled intersections. Further, to assess the traffic situation, the data on the traffic flow rate and its concentration are compared. Latest scientific studies propose a transition from spatial to temporal concentration. Therefore, the purpose of this work is to establish the regularities of the influence of traffic flow concentration in time on traffic flow rate at controlled city intersections. The methodological basis of this study was a systemic approach. Theoretical and experimental studies were based on the existing provisions of system analysis, traffic flow theory, experiment planning, impulses, probabilities, and mathematical statistics. Experimental data were obtained and processed using modern equipment and software: Traficam video detectors, SPECTR traffic light controller, Traficam Data Tool, SPECTR 2.0, AutoCad 2017, and STATISTICA 10. In the course of this study, the authors analyzed the dynamics of changes in the level of motorization, the structure of the motor vehicle fleet, and the dynamics of changes in the number of controlled intersections. As a result of theoretical studies, a hypothesis was put forward that the investigated process is described by a two-factor quadratic multiplicative model. Experimental studies determined the parameters of the developed model depending on the directions of traffic flow, and confirmed its adequacy according to Fisher’s criterion with a probability of at least 0.9. The results obtained can be used to control traffic flows at controlled city intersections.

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