scholarly journals The Impact of Traffic Crashes on Urban Network Traffic Flow

2019 ◽  
Vol 11 (14) ◽  
pp. 3956 ◽  
Author(s):  
Junwei Zeng ◽  
Yongsheng Qian ◽  
Bingbing Wang ◽  
Tingjuan Wang ◽  
Xuting Wei
Keyword(s):  
Traffic Flow ◽  
Network Traffic ◽  
Network Flow ◽  
Time Distribution ◽  
Urban Traffic ◽  
Extended Model ◽  
Traffic Network ◽  
Traffic Crashes ◽  
Urban Network ◽  
The Impact

This paper aims to investigate the impact of occasional traffic crashes on the urban traffic network flow. Toward this purpose, an extended model of coupled Nagel–Schreckenberg (NaSch) and Biham–Middleton–Levine (BML) models is presented. This extended model not only improves the initial conditions of the coupled models, but also gives the definition of traffic crashes and their spatial/time distribution. Further, we simulated the impact of the number of traffic crashes, their time distribution, and their spatial distribution on urban network traffic flow. This research contributes to the comprehensive understanding of the operational state of urban network traffic flow after traffic crashes, towards mastering the causes and propagation rules of traffic congestion. This work also a theoretical guidance value for the optimization of urban traffic network flow and the prevention and release of traffic crashes.

scholarly journals Traffic Inequality and Relations in Maritime Silk Road: A Network Flow Analysis

2021 ◽  
Vol 10 (1) ◽  
pp. 40
Author(s):  
Naixia Mou ◽  
Haonan Ren ◽  
Yunhao Zheng ◽  
Jinhai Chen ◽  
Jiqiang Niu ◽  
...  
Keyword(s):  
Traffic Flow ◽  
Network Flow ◽  
Road Traffic ◽  
Flow Analysis ◽  
Silk Road ◽  
Identification System ◽  
Traffic Network ◽  
Trajectory Data ◽  
Maritime Traffic ◽  
Maritime Silk Road

Maritime traffic can reflect the diverse and complex relations between countries and regions, such as economic trade and geopolitics. Based on the AIS (Automatic Identification System) trajectory data of ships, this study constructs the Maritime Silk Road traffic network. In this study, we used a complex network theory along with social network analysis and network flow analysis to analyze the spatial distribution characteristics of maritime traffic flow of the Maritime Silk Road; further, we empirically demonstrate the traffic inequality in the route. On this basis, we explore the role of the country in the maritime traffic system and the resulting traffic relations. There are three main results of this study. (1) The inequality in the maritime traffic of the Maritime Silk Road has led to obvious regional differences. Europe, west Asia, northeast Asia, and southeast Asia are the dominant regions of the Maritime Silk Road. (2) Different countries play different maritime traffic roles. Italy, Singapore, and China are the core countries in the maritime traffic network of the Maritime Silk Road; Greece, Turkey, Cyprus, Lebanon, and Israel have built a structure of maritime traffic flow in the eastern Mediterranean Sea, and Saudi Arabia serves as a bridge for maritime trade between Asia and Europe. (3) The maritime traffic relations show the characteristics of regionalization; countries in west Asia and the European Mediterranean region are clearly polarized, and competition–synergy relations have become the main form of maritime traffic relations among the countries in the dominant regions. Our results can provide a scientific reference for the coordinated development of regional shipping, improvement of maritime competition, cooperation strategies for countries, and adjustments in the organizational structure of ports along the Maritime Silk Road.

Dynamics of Urban Network Traffic flow during a Large-Scale Evacuation

2014 ◽  
Vol 2422 (1) ◽  
pp. 21-33 ◽  
Author(s):  
Ali Zockaie ◽  
Hani S. Mahmassani ◽  
Meead Saberi ◽  
Ömer Verbas
Keyword(s):  
Traffic Flow ◽  
Network Traffic ◽  
Large Scale ◽  
Urban Network

The impact of travelers’ rationality degree heterogeneity in the Advanced Traveler Information System on the network traffic flow evolution

SIMULATION ◽  
2017 ◽  
Vol 93 (6) ◽  
pp. 447-457 ◽  
Author(s):  
Jianqiang Wang ◽  
Shiwei Li
Keyword(s):  
Information System ◽  
Traffic Flow ◽  
Network Traffic ◽  
Mixed Logit ◽  
Evolution Model ◽  
Traffic Information ◽  
Traveler Information ◽  
Integrated Simulation ◽  
Advanced Traveler Information System ◽  
The Impact

The interplay between traffic information, which is normally distributed by the Advanced Traveler Information System (ATIS) and travelers’ decision behaviors, is prone to lead to high complexity in the evolution process of network traffic flow. Considering the obvious heterogeneity that is reflected in the numerous ways that travelers adopt ATIS information and choose routes, the lognormal distribution is adopted to describe the heterogeneity of travelers’ rationality degree. Introducing habitual factors of traveler route choice, modeling ideas of Multi-Agent and Mixed Logit are utilized to construct the day-to-day evolution model of network traffic flow, which is based on the value difference of travelers’ cognitive travel time. Furthermore, an integrated simulation algorithm based on the Monte Carlo method is specially designed to solve the previous evolution model. The simulation indicates that a lower individual difference and a higher rationality degree would lead to a more obvious aggregation phenomenon of network traffic flow and inefficiency of operation in road networks.

Analysis of Dynamic Impedance Functions in Urban Traffic Flow Guidance System

2012 ◽  
Vol 238 ◽  
pp. 503-506 ◽  
Author(s):  
Zhi Cheng Li
Keyword(s):  
Traffic Flow ◽  
Network Model ◽  
Large Scale ◽  
Choice Model ◽  
Transportation Systems ◽  
Urban Traffic ◽  
Guidance System ◽  
Traffic Network ◽  
Dynamic Traffic ◽  
Run Time

The successful application of Intelligent Transportation Systems (ITS) depends on the traffic flow at any time with high-precision and large-scale assessments, it is necessary to create a dynamic traffic network model to evaluate and forecast traffic. Dynamic route choice model sections of the run-time function are very important to the dynamic traffic network model. To simplify the dynamic traffic modeling, improve the calculation accuracy and save computation time, the flow on the section of the interrelationship between the exit flow and number of vehicles are analyzed, a run-time functions into the flow using only sections of the said sections are established.

Development of Guidelines Based on Life-Cycle Cost To Replace Level-of-Service Concept in Capacity Analysis

1997 ◽  
Vol 1572 (1) ◽  
pp. 10-17
Author(s):  
Karl-L. Bang ◽  
Gunnar Lindberg ◽  
Gandhi Harahap
Keyword(s):  
Life Cycle ◽  
Traffic Flow ◽  
Traffic Engineering ◽  
Life Cycle Cost ◽  
Developed Countries ◽  
Urban Traffic ◽  
Level Of Service ◽  
Service Concept ◽  
The Impact ◽  
Selection Of

Highway capacity manuals (HCMs) from developed countries cannot be successfully applied in Indonesia because of significant differences in driver behavior, traffic composition, and level of roadside activities. The Indonesian HCM project (IHCM) was therefore started in 1991 and has resulted in a manual and software for urban traffic facilities, inter-urban roads, and motorways. The IHCM also includes traffic engineering guidelines for selection of appropriate road and intersection type and design for new construction or improvements based on life-cycle cost (LCC) analysis. The LCC model includes all relevant road-user costs (those for vehicle operations, time, accidents, and emissions) and road-producer costs (those for land acquisition, road construction, and road maintenance and operation). The LCC results identify the design alternative that has the lowest total cost and thus is the most economical for any given traffic flow. The IHCM guidelines also include traffic-performance graphs for standard road types and intersections as a function of traffic flow as well as information about accident rates and the impact of geometric design changes on safety. The guidelines assist the user with preliminary selection of the design before starting the detailed analysis. They can also be used on their own as a shortcut for planning purposes and therefore serve as a replacement for the level-of-service concept applied in the U.S. HCM.

scholarly journals Determination of the Model Basis for Assessing the Vehicle Energy Efficiency in Urban Traffic

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8538
Author(s):  
Miroslaw Śmieszek ◽  
Nataliia Kostian ◽  
Vasyl Mateichyk ◽  
Jakub Mościszewski ◽  
Liudmyla Tarandushka
Keyword(s):  
Energy Efficiency ◽  
Standard Deviation ◽  
Traffic Flow ◽  
Urban Traffic ◽  
Urban Transport ◽  
Functional Elements ◽  
Energy Unit ◽  
Relative Standard ◽  
Input Parameters ◽  
The Impact

The paper studies the problem of assessing the vehicle energy efficiency on the streets of urban road network. As a result of morphological analysis of the system “Vehicle—Traffic flow—Road—Traffic Environment” 18 significant morphological attributes of its functional elements, that affect the energy efficiency of vehicles, were identified. Each attribute is characterized by 3–6 implementation variants, which are evaluated by the relevant quantitative or qualitative parameters. The energy efficiency of vehicles is determined by the criteria of their energy consumption considering the vehicle category, type of energy unit, mode of vehicle movement and adjustment factors—road, climatic and others. The input parameters values of the system in the process of traffic flow on the linear fragments of streets and road networks of the cities of Ukraine and Poland were measured. The set of independent system parameters is determined by applying the Farrar-Glober method based on statistical estimates. The specified set is the basis of the studied system and is formed of 10 independent input parameters. The presence in the basis of parameters that correspond to the morphological features of all four functional elements, confirmed the importance of these elements of the system. The mathematical dependence of the impact of vehicle characteristics, traffic flow, road and environment on vehicle energy efficiency is built. The standard deviation of the model values from the tabular ones equals σ´=0.0091. Relative standard deviation equals S´r=1.5%. The results of the study could be used in the development of new and optimization of existing intelligent traffic control systems of urban transport.

Improve urban traffic efficiency with prohibiting left-turn policy

2021 ◽  
Author(s):  
Meng-Qin Cheng ◽  
Lele Zhang ◽  
Xue-Dong Hu ◽  
Mao-Bin Hu
Keyword(s):  
Traffic Flow ◽  
Traffic Management ◽  
Critical Length ◽  
Urban Traffic ◽  
Flow Density ◽  
Route Guidance ◽  
Left Turn ◽  
Traffic Efficiency ◽  
Quickest Path ◽  
The Impact

Enhancing traffic flow plays an important role in the traffic management of urban arterial networks. The policy of prohibiting left-turn (PLT) at selected highly demanded intersections has been adopted as an attempt to increase the efficiency at these intersections. In this paper, we study the impact of PLT by mathematical analysis and simulations based on the cellular automaton model. Using the flow-density relation, three system performance indexes are examined: the average trip completion rate, the average traffic flow, and the average velocity of vehicles. Different route guidance strategies, including the shortest path and the quickest path, are investigated. We show that when left turn is prohibited, vehicles are distributed more homogeneously in the road network, and the system performs better and reaches a higher capacity. We also derive a critical length of link, above which the benefit of PLT will decrease.

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