scholarly journals Application of Mathematical Modeling Methods for Operational Optimization of Urban Traffic in an Accident on a Section of the Road Network

2021 ◽  
Vol 9 (7) ◽  
pp. 2140-2146
Author(s):  
Natalya Alexandrovna Naumova
2022 ◽  
Vol 13 (2) ◽  
pp. 1-25
Author(s):  
Bin Lu ◽  
Xiaoying Gan ◽  
Haiming Jin ◽  
Luoyi Fu ◽  
Xinbing Wang ◽  
...  

Urban traffic flow forecasting is a critical issue in intelligent transportation systems. Due to the complexity and uncertainty of urban road conditions, how to capture the dynamic spatiotemporal correlation and make accurate predictions is very challenging. In most of existing works, urban road network is often modeled as a fixed graph based on local proximity. However, such modeling is not sufficient to describe the dynamics of the road network and capture the global contextual information. In this paper, we consider constructing the road network as a dynamic weighted graph through attention mechanism. Furthermore, we propose to seek both spatial neighbors and semantic neighbors to make more connections between road nodes. We propose a novel Spatiotemporal Adaptive Gated Graph Convolution Network ( STAG-GCN ) to predict traffic conditions for several time steps ahead. STAG-GCN mainly consists of two major components: (1) multivariate self-attention Temporal Convolution Network ( TCN ) is utilized to capture local and long-range temporal dependencies across recent, daily-periodic and weekly-periodic observations; (2) mix-hop AG-GCN extracts selective spatial and semantic dependencies within multi-layer stacking through adaptive graph gating mechanism and mix-hop propagation mechanism. The output of different components are weighted fused to generate the final prediction results. Extensive experiments on two real-world large scale urban traffic dataset have verified the effectiveness, and the multi-step forecasting performance of our proposed models outperforms the state-of-the-art baselines.


2018 ◽  
Vol 115 (50) ◽  
pp. 12654-12661 ◽  
Author(s):  
Luis E. Olmos ◽  
Serdar Çolak ◽  
Sajjad Shafiei ◽  
Meead Saberi ◽  
Marta C. González

Stories of mega-jams that last tens of hours or even days appear not only in fiction but also in reality. In this context, it is important to characterize the collapse of the network, defined as the transition from a characteristic travel time to orders of magnitude longer for the same distance traveled. In this multicity study, we unravel this complex phenomenon under various conditions of demand and translate it to the travel time of the individual drivers. First, we start with the current conditions, showing that there is a characteristic time τ that takes a representative group of commuters to arrive at their destinations once their maximum density has been reached. While this time differs from city to city, it can be explained by Γ, defined as the ratio of the vehicle miles traveled to the total vehicle distance the road network can support per hour. Modifying Γ can improve τ and directly inform planning and infrastructure interventions. In this study we focus on measuring the vulnerability of the system by increasing the volume of cars in the network, keeping the road capacity and the empirical spatial dynamics from origins to destinations unchanged. We identify three states of urban traffic, separated by two distinctive transitions. The first one describes the appearance of the first bottlenecks and the second one the collapse of the system. This collapse is marked by a given number of commuters in each city and it is formally characterized by a nonequilibrium phase transition.


Author(s):  
D. P. Khodoskin

Purpose. Often, the existing level of traffic capacity of road network facilities in large cities is insufficient. This is often due to the fact that urban growth is significantly ahead of the reconstruction and renovation of the corresponding infrastructure. As a result, traffic delays of various kinds occur on city roads, accompanied, first of all, by economic losses. Therefore, the search for reserves to reduce various types of losses associated with insufficient traffic capacity of the road network when organizing urban traffic is the purpose of this work. Methodology To determine the reserves for increasing the traffic capacity of the road network and reducing various kinds of delays, the method of deterministic analysis was used, the method for calculating the cycle according to F. Webster, based on the use of phase coefficients and time lost in the cycle (as the sum of transient intervals), the method for measuring the intensity of car traffic in the traffic flow, as well as the methodology for calculating economic losses arising from delays in the movement of vehicles. Findings. A study of delays and time expenditures and the corresponding economic losses that occur at typical objects of the city's street-road network (regulated intersections) has been carried out. The reserves of their reduction, and as a consequence, the increase in the capacity of both individual sections and the city's road network as a whole, have been determined. Originality. The use of this method on real objects of the road network allows developing the scientific interpretation of the methods used and expanding the scope of their application. Practical value. Assessment of emerging problems of traffic capacity and associated losses (including economic ones) makes it possible to determine the most promising ways to determine the traffic capacity reserves and, as a result, reduce economic losses.


Author(s):  
Yi Li ◽  
Weifeng Li ◽  
Qing Yu ◽  
Han Yang

Urban traffic congestion is one of the urban diseases that needs to be solved urgently. Research has already found that a few road segments can significantly influence the overall operation of the road network. Traditional congestion mitigation strategies mainly focus on the topological structure and the transport performance of each single key road segment. However, the propagation characteristics of congestion indicate that the interaction between road segments and the correlation between travel speed and traffic volume should also be considered. The definition is proposed for “key road cluster” as a group of road segments with strong correlation and spatial compactness. A methodology is proposed to identify key road clusters in the network and understand the operating characteristics of key road clusters. Considering the correlation between travel speed and traffic volume, a unidirectional-weighted correlation network is constructed. The community detection algorithm is applied to partition road segments into key road clusters. Three indexes are used to evaluate and describe the characteristic of these road clusters, including sensitivity, importance, and IS. A case study is carried out using taxi GPS data of Shanghai, China, from May 1 to 17, 2019. A total of 44 key road clusters are identified in the road network. According to their spatial distribution patterns, these key road clusters can be classified into three types—along with network skeletons, around transportation hubs, and near bridges. The methodology unveils the mechanism of congestion formation and propagation, which can offer significant support for traffic management.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
ZhaoWei Qu ◽  
Yan Xing ◽  
XianMin Song ◽  
YuZhou Duan ◽  
Fulu Wei

The interactions between signal setting and traffic assignment can directly affect the urban road network efficiency. In order to improve the coordination of signal setting with traffic assignment, this paper created a traffic control algorithm considering traffic assignment; meanwhile, the link impedance function and the route choice function were introduced into this paper to study the user's route choice and the road network flow distribution. Then based on the above research, we created a system utility value model. Finally through the VISSIM software to simulate the test network, we verified the superiority of the coordination algorithm and the model and gave the optimal flow of the road network.


2019 ◽  
Vol 296 ◽  
pp. 02002
Author(s):  
Mohamad Shatanawi ◽  
Souhir Boudhrioua ◽  
Ferenc Mészáros

Worldwide, multiple studies have been trying to reduce traffic issues without physically changing the road network, this is when the congestion fees strategy has been considered as a favorable solution for the urban traffic issues. A fundamental condition that needs to be checked before the implementation of the road-pricing scheme is the acceptability of both the political and the public parties. The acceptability is so variable and depends on many features and differs from one individual to another, thus, a survey with a set of variant questions might help to understand the expectations and the worries of the citizens and aim to improve them for better effectiveness of the road-pricing project. This report aims, through analyzing the responses of a distributed survey, to evaluate the acceptability of the citizens of Tunis, Tunisia and Damascus, Syria in order to draw a comparison between the two cities. Moreover, it assesses the degree of acceptability and the variable expectations of the implementation of the congestion fees of the two societies.


Author(s):  
Hao She ◽  
Xingsheng Xie

Urban traffic congestion seriously affects the traffic efficiency, causing travel delays and resources wasted directly. In this paper, a road network pre-partitioning method with priority for congestion control is proposed to reduce traffic congestion. Traffic flow feature is extracted based on CNN, and the estimated accuracy of intersection reach 95.32% through CNN-SVM model. Subarea congestion coefficient and intersection merger coefficient are defined to expand the control area of congestion coordination. The association and similarity of intersections are considered using spectral clustering for non-congested intersection partitioning. The results show that the congestion priority control partition method reduces a congestion intersection compared to directly using spectral clustering for subarea partition, and reduces the road network congestion coefficient by 0.05 after 30 minutes than directly using spectral clustering, which is an effective subarea partition method.  


2019 ◽  
Vol 16 (6) ◽  
pp. 670-679 ◽  
Author(s):  
I. E. Agureev ◽  
D. A. Yurchenko

Introduction. The load models of the road network make it possible to understand a lot of the transport, social, environmental, and other city problems. Creating transport models requires knowledge of the traffic flows’ formation and functioning. The paper formulates a goal and poses tasks for the research conducting of the adjoining territories of residential areas in Tula as one of the urban traffic flows’ sources and of the identifying patterns of the parking places near houses’ influence on the road network loading.Materials and methods. The basis of the research was the development in the field of predictive simulation of automobile transport systems. The authors used complex of computer-aided design “TransNet”, which allowed adjusting the initial data in the base model by the results of the parking places’ functioning.Discussion and conclusions. As a result, the improved transport model of Tula allows making the forecast for determining the main parameters of the transport system taking into account the dynamics of vehicles’ local area departure at different time intervals. Moreover, the proposed methodological tools and algorithm for solving the problem of the road network loading in a quasi-dynamic setting helps to solve existing transport problems and to improve the traffic organization.The authors have read and approved the final manuscript. Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.


Author(s):  
Кадасев ◽  
D. Kadasev ◽  
Коротнев ◽  
V. Korotnev

This article describes a practical method of constructing mathematical models of traffic flow, the most suitable for a particular city highway. The initial data are: instant speed, time, distance, flux density, intensity of movement of vehicles. Using the obtained data, built regression model, and conducted correlation analysis. The choice of the mathematical model that most faithfully describes the transport process was made on the basis of the correlation coefficient


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