scholarly journals Left-Side On-Ramp Metering for Improving Safety and Efficiency in Underground Expressway Systems

2019 ◽  
Vol 11 (12) ◽  
pp. 3247 ◽  
Author(s):  
Minhua Shao ◽  
Congcong Xie ◽  
Lijun Sun ◽  
Xiaomin Wan ◽  
Zhang Chen
Keyword(s):  
Traffic Flow ◽  
Traffic Safety ◽  
Traffic Control ◽  
Flow Characteristics ◽  
Ramp Metering ◽  
Accident Risk ◽  
Data Traffic ◽  
Traffic Efficiency ◽  
Traffic Characteristics ◽  
Two Parameter

As one of the effective measures of intelligent traffic control, on-ramp metering is often used to improve the traffic efficiency of expressways. Existing on-ramp metering research mainly discusses expressways with right-side on-ramps. However, for underground expressway systems (UESs), left-side on-ramps are frequently adopted to reduce the ground space occupied by ramp construction. Since traffic entering from the left and right sides of the mainline may have different traffic characteristics, on-ramp metering for UESs with left-side on-ramps should be explored specifically. This study examines the impacts of left-side on-ramps on the traffic safety and efficiency of UESs and proposes an effective on-ramp metering strategy. Firstly, using field data, traffic flow fundamental diagrams and speed dispersion are discussed to explore the traffic flow characteristics of the “left-in” UES. The results show that the capacity and critical occupancy are both reduced in left-side on-ramp compared to right-side on-ramp expressways. Meanwhile, the speed dispersion is higher in left-side on-ramp UESs, which means a higher accident risk. Based on this, considering traffic safety and efficiency, a novel two-parameter left-side on-ramp metering strategy for UESs is proposed, in which occupancy and speed are used as the control indicators simultaneously. Additionally, the mechanism of the metering strategy is explained. Finally, the proposed on-ramp metering strategy is simulated on a real UES. The results demonstrate the advantages of the proposed two-parameter on-ramp metering strategy for improving the traffic safety and efficiency of UESs.

scholarly journals STUDY ON HETEROGENEOUS TRAFFIC FLOW CHARACTERISTICS OF A TWO-LANE ROAD / HETEROGENINIO TRANSPORTO EISMO SRAUTO CHARAKTERISTIKOS DVIEJŲ JUOSTŲ KELYJE / ХАРАКТЕРИСТИКИ ГЕТЕРОГЕННОГО ПОТОКА ДВИЖЕНИЯ НА ДВУХПОЛОСНОЙ ДОРОГЕ

Transport ◽  
2011 ◽  
Vol 26 (2) ◽  
pp. 185-196 ◽  
Author(s):  
Nitish Sharma ◽  
Shriniwas Shrikant Arkatkar ◽  
Ashoke Kumar Sarkar
Keyword(s):  
Traffic Flow ◽  
Exploratory Study ◽  
Flow Characteristics ◽  
Heterogeneous Traffic ◽  
Data Traffic ◽  
Traffic Characteristics ◽  
Flow Parameters ◽  
Traffic Flow Characteristics

The paper presents traffic studies conducted by using a video capturing technique on the uninterrupted heterogeneous mix of vehicles plying on an undivided two-lane road facility. On the basis of the collected data, traffic characteristics pertaining to arrival, headway and speed distributions have been plotted considering suitable mathematical distributions to fit field observed values. The curves representing fundamental traffic flow relationships among three basic variables, namely speed, density and flow have also been established. Thus, a systematic attempt to enable the understanding of heterogeneous traffic flow parameters has been made through this exploratory study. Santrauka Remiantis vaizdo technika gautais duomenimis, straipsnyje tyrinėjami nenutrūkstami įvairių transporto priemonių srautai dviejų juostų vientisame kelyje. Darbe pateikiamas eismo srauto charakteristikų, susijusių su atvykimu, judėjimu į priekį ir greičio pasiskirstymu, planas, atsižvelgiant į tinkamą matematinį planavimą, sėkmingai derinamą su jau stebėtomis reikšmėmis. Pateiktos fundamentalios transporto eismo srauto grafinės priklausomybės nuo trijų pagrindinių kintamųjų – greičio, tankio ir srauto. Sistemingas tyrimas leidžia geriau suprasti heterogeninio (įvairiarūšio) transporto eismo srauto parametrus. Резюме Исследуется непрерывное движение различных транспортных средств в потоке на двухполосной дороге с использованием данных, полученных с помощью видеотехники. Представлен план характери стик потока движения с учетом прибытия, движения вперед и распределения скорости. Математический эксперимент удачно сочетается с уже имеющимися значениями. Представлены фундаментальные графические зависимости потока движения от трех основных переменных – скорости, плотности и потока. Системное исследование позволит лучше понять параметры гетерогенного потока движения транспорта.

scholarly journals Semi-Continuous Spatial Statistical Analysis Using AIS Data for Vessel Traffic Flow Characteristics in Fairway

2021 ◽  
Vol 9 (4) ◽  
pp. 378
Author(s):  
Jong Kwan Kim
Keyword(s):  
Statistical Analysis ◽  
Traffic Flow ◽  
Flow Characteristics ◽  
Automatic Identification ◽  
Identification System ◽  
Spatial Statistical Analysis ◽  
Traffic Characteristics ◽  
Traffic Distribution ◽  
Traffic Flow Characteristics ◽  
Marine Accidents

As high vessel traffic in fairways is likely to cause frequent marine accidents, understanding vessel traffic flow characteristics is necessary to prevent marine accidents in fairways. Therefore, this study conducted semi-continuous spatial statistical analysis tests (the normal distribution test, kurtosis test and skewness test) to understand vessel traffic flow characteristics. First, a vessel traffic survey was conducted in a designated area (Busan North Port) for seven days. The data were collected using an automatic identification system and subsequently converted using semi-continuous processing methods. Thereafter, the converted data were used to conduct three methods of spatial statistical analysis. The analysis results revealed the vessel traffic distribution and its characteristics, such as the degree of use and lateral positioning on the fairway based on the size of the vessel. In addition, the generalization of the results of this study along with that of further studies will aid in deriving the traffic characteristics of vessels on the fairway. Moreover, these characteristics will reduce maritime accidents on the fairway, in addition to establishing the foundation for research on autonomous ships.

scholarly journals Developing a New Spatial Unit for Macroscopic Safety Evaluation Based on Traffic Density Homogeneity

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Chen Wang ◽  
Lin Liu ◽  
Chengcheng Xu
Keyword(s):  
Traffic Flow ◽  
Traffic Control ◽  
Flow Characteristics ◽  
Traffic Density ◽  
Minimization Method ◽  
Spatial Unit ◽  
Flow Parameters ◽  
Safety Knowledge ◽  
Traffic Operation ◽  
Crash Modeling

Macrolevel crash modeling has been extensively applied to investigate the safety effects of demographic, socioeconomic, and land use factors, in order to add safety knowledge into traffic planning and policy-making. In recent years, with the increasing attention to regional traffic management and control, the safety effects of macrolevel traffic flow parameters may also be of interest, in order to provide useful safety knowledge for regional traffic operation. In this paper, a new spatial unit was developed using a recursive half-cut partitioning procedure based on a normalized cut (NC) minimization method and traffic density homogeneity. Two Bayesian lognormal models with different conditional autoregressive (CAR) priors were applied to examine the safety effects of traffic flow characteristics at the NC level. It was found that safety effects of traffic flow exist at such macrolevel, indicating the necessity of considering safety for regional traffic control and management. Furthermore, traffic flow effects were also examined for another two spatial units: Traffic Analysis Zone (TAZ) and Census Tract (CT). It was found that ecological fallacy and atomic fallacy could exist without considering traffic flow parameters at those planning-based levels. In general, safety needs to be considered for regional traffic operation and the effects of traffic flow need to be considered for spatial crash modeling at various spatial levels.

Application of Catastrophe Theory in Traffic Flow of Highway Tunnel Group

2013 ◽  
Vol 734-737 ◽  
pp. 1609-1612
Author(s):  
Wei Zhan ◽  
Yue Quan Shang ◽  
Feng Xia Chi
Keyword(s):  
Traffic Flow ◽  
Traffic Control ◽  
Catastrophe Theory ◽  
Critical Density ◽  
Flow Characteristics ◽  
Control Measures ◽  
Highway Tunnel ◽  
Relationship Of ◽  
The Relationship ◽  
Highway Management

Based on the investigation of traffic flow in a typical highway tunnel group, the traffic flow characteristics were analyzed by catastrophe theory with the relationship of the speed, volume and density. The discontinuous leaping change phenomenon of the traffic data under large traffic volume is better explained by the catastrophe model than the traditional ways. The value of critical density can be obtained by analyzing the critical state of traffic flow. Then the traffic flow warning can be realized in highway tunnel group region. The data and results can be used for the reference of taking traffic control measures by highway management.

scholarly journals Portable Telematic System as an Effective Traffic Flow Management in Workzones

2015 ◽  
Vol 16 (2) ◽  
pp. 99-106 ◽  
Author(s):  
Marek Ščerba ◽  
Tomáš Apeltauer ◽  
Jiří Apeltauer
Keyword(s):  
Traffic Flow ◽  
Traffic Safety ◽  
Traffic Control ◽  
Traffic Management ◽  
Traffic Accidents ◽  
Intelligent System ◽  
Economic Losses ◽  
Road Users ◽  
Traffic Flow Management ◽  
Negative Impacts

Abstract Traffic infrastructure localities with temporal restrictions for example due to reconstructions, or modernization, are important aspects influencing the traffic safety and traffic flow. On the basis of our research, we can identify main factors, which generate travel time loses, and which often cause traffic accidents in bottlenecks. First of all, it is improper late merge, speeding, tailgating, lower tolerance and consideration to other road users. Nervousness and ignorance of drivers also play an important role in generation of traffic congestions, lower level of service and resulting external economic loses. One of the tools eliminating the traffic restriction negative impacts is usage of portable telematics systems. In 2011 to 2013,project ViaZONE was in progress, which was to design an intelligent system with the aim to eliminate the mentioned risks and reduce economic losses generated by traffic congestions. Using available data and information, we have proved profitability and cost-effectiveness of dynamic systems for traffic control of work zones. Regarding traffic management, the system showed some problems due to indisciplined drivers and the system proved that speeding in these hazardous road segments is a common practice which caused accidents and congestions.

scholarly journals Analyzing the Influence of Mobile Phone Use of Drivers on Traffic Flow Based on an Improved Cellular Automaton Model

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Yao Xiao ◽  
Jing Shi
Keyword(s):  
Cellular Automaton ◽  
Traffic Flow ◽  
Flow Rate ◽  
Traffic Safety ◽  
Model Simulation ◽  
Cellular Automaton Model ◽  
Mobile Phone Use ◽  
Traffic Efficiency ◽  
A Value ◽  
Ca Model

This paper aimed to analyze the influence of drivers’ behavior of phone use while driving on traffic flow, including both traffic efficiency and traffic safety. An improved cellular automaton model was proposed to simulate traffic flow with distracted drivers based on the Nagel-Schreckenberg model. The driving characters of drivers using a phone were first discussed and a value representing the probability to use a phone while driving was put into the CA model. Simulation results showed that traffic flow rate was significantly reduced if some drivers used a phone compared to no phone use. The flow rate and velocity decreased as the proportion of drivers using a phone increased. While, under low density, the risk of traffic decreased first and then increased as the distracted drivers increased, the distracted behavior of drivers, like using a phone, could reduce the flow rate by 5 percent according to the simulation.

scholarly journals Impacts of Autonomous Vehicles on Traffic Flow Characteristics under Mixed Traffic Environment: Future Perspectives

2021 ◽  
Vol 13 (19) ◽  
pp. 11052
Author(s):  
Mohammed Al-Turki ◽  
Nedal T. Ratrout ◽  
Syed Masiur Rahman ◽  
Imran Reza
Keyword(s):  
Traffic Flow ◽  
Autonomous Vehicles ◽  
Penetration Rate ◽  
Flow Characteristics ◽  
Driving Behavior ◽  
Mixed Traffic ◽  
Traffic Characteristics ◽  
Traffic Environment ◽  
Traffic Flow Characteristics ◽  
The Impact

Vehicle automation and communication technologies are considered promising approaches to improve operational driving behavior. The expected gradual implementation of autonomous vehicles (AVs) shortly will cause unique impacts on the traffic flow characteristics. This paper focuses on reviewing the expected impacts under a mixed traffic environment of AVs and regular vehicles (RVs) considering different AV characteristics. The paper includes a policy implication discussion for possible actual future practice and research interests. The AV implementation has positive impacts on the traffic flow, such as improved traffic capacity and stability. However, the impact depends on the factors including penetration rate of the AVs, characteristics, and operational settings of the AVs, traffic volume level, and human driving behavior. The critical penetration rate, which has a high potential to improve traffic characteristics, was higher than 40%. AV’s intelligent control of operational driving is a function of its operational settings, mainly car-following modeling. Different adjustments of these settings may improve some traffic flow parameters and may deteriorate others. The position and distribution of AVs and the type of their leading or following vehicles may play a role in maximizing their impacts.

scholarly journals Research on Joint Control of On-Ramp Metering and Mainline Speed Guidance in the Urban Expressway Based on MPC and Connected Vehicles

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Lina Wu ◽  
Yusheng Ci ◽  
Yichen Sun ◽  
Wei Qi
Keyword(s):  
Traffic Safety ◽  
Traffic Control ◽  
Control Method ◽  
Operational Efficiency ◽  
Ramp Metering ◽  
Joint Control ◽  
Connected Vehicles ◽  
Control Methods ◽  
Guidance Control ◽  
Urban Expressway

The traffic operational efficiency of the urban expressway system will affect one of the entire cities. Moreover, the idea that traffic control can improve the traffic operational efficiency of the urban expressway system has been fully confirmed. At present, the main control methods include on-ramp metering and speed guidance control. However, there is a gap in using these two control methods together, such as unclear application conditions and unsystematic methods. In this paper, on-ramp metering and speed guidance control are combined effectively. Based on the research of METANET macroscopic traffic flow model and model predictive control (MPC), a novel joint control method based on MPC and connected vehicles (CVs) for on-ramp metering and speed guidance control of the urban expressway is proposed. Finally, the simulation results show that the proposed control method can effectively improve the traffic efficiency and traffic safety.

Research on the Real-Time Prediction Model of the Traffic Flow Based on Wavelet Neural Network

2012 ◽  
Vol 241-244 ◽  
pp. 2088-2094
Author(s):  
Hui Ying Wen ◽  
Gui Feng Yang ◽  
Wei Tiao Wu
Keyword(s):  
Neural Network ◽  
Real Time ◽  
Traffic Flow ◽  
Traffic Safety ◽  
Traffic Control ◽  
Wavelet Neural Network ◽  
Mountain Area ◽  
Analog Simulation ◽  
Traffic Flow Prediction ◽  
Real Time Traffic

Real-time traffic flow prediction is the core of traffic control and management, which is the basis of traffic safety in mountain area. Traffic flow, which is highly time-relevant, with the features of high non-linear and non-determinism, can be treated as the time sequence forecast. Considering these features, this paper deals specially with this issue based on Wavelet neural network. Besides, by taking a road in mountain area for example, the paper realizes the analog simulation through the Matlab software programming. And the simulation results show that the traffic flow can be precisely forecast using Wavelet neural network, and its value is close to the expectations. The MAE of the Wavelet neural network is 20.1074 and the MSE is 2.5254.

Study on Control Design of Interchange Entrance Congestion Zone

2013 ◽  
Vol 361-363 ◽  
pp. 2270-2275
Author(s):  
Xian Guang Wang ◽  
Xiao Nian Sun
Keyword(s):  
Traffic Safety ◽  
Control Strategy ◽  
Traffic Control ◽  
High Speed ◽  
Road Network ◽  
Control Strategies ◽  
Operational Reliability ◽  
Traffic Demand ◽  
Traffic Characteristics ◽  
Overall Reliability

Interchange entrance area is the key point which affects the overall operational reliability of an Interchange. In order to alleviate the crowded ramp merging area, improve the overall reliability of the interchange and improve traffic safety, when traffic demand increases to a certain extent, traffic control strategies should be used. According of the characteristics of the interchange ramp entrance area, the control strategy of interchange and the mainline which affect the reliability of high-speed road network most has been researched. Analyzing the geometric and traffic characteristics of the ramp merging area, different control strategies on the ramp and the mainline are proposed, that is ramp access control strategy and the main line lane running constraint strategy.

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