Modeling of Urban Road Network Traffic Carrying Capacity Based on Equivalent Traffic Flow

2021 ◽  
pp. 102462
Author(s):  
Yuhong Gao ◽  
Zhaowei Qu ◽  
Xianmin Song ◽  
Zhenyu Yun
Keyword(s):  
Traffic Flow ◽  
Carrying Capacity ◽  
Network Traffic ◽  
Road Network ◽  
Urban Road Network ◽  
Urban Road

scholarly journals Effects of static bottlenecks on traffic flow in urban road network

2020 ◽  
Vol 12 (3) ◽  
pp. 1-15
Author(s):  
John N.P. Mahona ◽  
Cuthbert F. Mhilu ◽  
Joseph Kihedu ◽  
Hannibal Bwire
Keyword(s):  
Traffic Flow ◽  
Road Network ◽  
Traffic Density ◽  
Urban Road Network ◽  
Peak Period ◽  
Flow Models ◽  
Urban Road ◽  
Stop And Go ◽  
Traffic Flow Models ◽  
Methodological Aspects

Existing traffic flow models do not consider the effects of road static bottlenecks on traffic flow. In this paper, a modified macroscopic continuum  model for traffic flow on urban road network with static bottlenecks is presented. The model takes into account the fluctuations of traffic flow considering static bottlenecks during the morning peak period. The model results show that existence of static road bottlenecks with various configurations cause traffic flow instabilities. This phenomenon lead into stop-and-go traffic flow conditions under the moderate density and reduction of the traffic system’s efficiency. Furthermore, results show that an increase in traffic density is accompanied by a significant decrease of speed which adversely influences performance of roadway and decrease the traffic system’s efficiency and thus resulting to the occurrence of congestions. The methodological aspects of the study and results will enable traffic engineers and planners to assess and improve existing urbanroad networks. Keywords: Traffic flow, Bottlenecks, stability, Stop-and-go traffic, System’s efficiency, Congestion.

Cascade defense in urban road network by inserting modular topologies

Kybernetes ◽  
2014 ◽  
Vol 43 (5) ◽  
pp. 750-763 ◽  
Author(s):  
Zhiyun Zou ◽  
Jinlong Wu ◽  
Jianzhi Gao ◽  
Xuecai Xu
Keyword(s):  
Traffic Flow ◽  
Road Network ◽  
Random Network ◽  
Small World ◽  
User Equilibrium ◽  
Cascading Failures ◽  
Urban Road Network ◽  
Content Type ◽  
Urban Road ◽  
Critical Components

Purpose – By aiming at defending cascade failures effectively, the purpose of this paper is to present a strategy of inserting modular topologies into urban road network through reducing the burdens of critical components with too much traffic flow. Design/methodology/approach – Each module is considered as a small-world random network, which is inserted into the initial Barabási-Albert scale-free network. Based on the user-equilibrium assignment, the strategy searches for remote nodes with low betweeness and flow in the network, and sets these nodes to be connected with the modular topologies. In this sense, the inserted modules are supposed to attach to the nodes with lower intensity of shorter path, and avoid bringing more impact to the nodes with higher betweeness and traffic flow. By using efficiency as the measurement of cascading failures, the performance of the networks generated through the strategy is tested. Findings – The results show that the performance of the strategy is sensitive to the average degree of the inserted modular, and the modular size with a better effect on reducing the size of cascading failures or delaying the time of breakdown, while the other factors (e.g. the rewired probability) present few differences among various values. Meanwhile, it is found that the importance-based attachment mechanism has a better effect on preventing the cascading failures, especially delaying the step time of the larger reduction. Practical implications – The strategy aims at alleviating the burdens in critical components to prevent the cascading failures of the network, and provides practical guidance on the decision of the urban road network evolving process. Originality/value – An effective strategy for cascade defense in urban road network is proposed in this paper.

scholarly journals Urban Road Network Emergency: An Integrative Vulnerability Identification Method

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Huaikun Xiang
Keyword(s):  
Network Traffic ◽  
Road Network ◽  
Road Networks ◽  
Likelihood Method ◽  
Survey Method ◽  
Urban Road Network ◽  
Urban Road ◽  
The Road ◽  
Identification Method ◽  
The Impact

The vulnerability of an urban road network is affected by many factors, such as internal road network layout, network structure strength, and external destructive events, which have great uncertainty and complexity. Thus, there is still no unified and definite vulnerability analysis scheme available to cities. This paper proposes an integrative vulnerability identification method for urban road networks, which mainly relates to the vulnerability connotation and characteristics analysis of urban road networks during emergency, and vulnerability comprehensive evaluation indices design based on urban road network connectivity, traffic efficiency and performance, and an empirical study on a vulnerability identification method of an urban road network. In the empirical case, a real road network and traffic operation data were used from Science and Technology Park of Shenzhen City, China. In the context of one certain emergency scenario, the stated preference survey method and maximum likelihood method are used to solve the road users’ random travel choice behavior parameters; subsequently, based on the traffic equilibrium distribution prediction, the traffic vulnerability identification methods of the road network in this region were verified before and after the emergency. The method presented here not only considers the impact of network topology changes on road network traffic function during emergency but also considers the impact of dynamic changes in road network traffic demand on vulnerability; therefore, it is closer to the actual distribution of urban road network traffic vulnerability.

Sign in / Sign up

Export Citation Format

Share Document