scholarly journals Identification of parameters and verification of an urban traffic flow model. A case study in Wrocław

2018 ◽  
Vol 23 ◽  
pp. 00005 ◽  
Author(s):  
Mieczysław Chalfen ◽  
Joanna A. Kamińska
Keyword(s):  
Traffic Flow ◽  
Transport System ◽  
Time Of Day ◽  
Urban Traffic ◽  
Traffic Density ◽  
Intelligent Transport System ◽  
Identification Of Parameters ◽  
Hourly Data ◽  
The Impact ◽  
The City

A macroscopic model of road traffic flow in an entire city is constructed, using the example of Wrocław. The model is of deterministic-random type. The start and finish points of each vehicle journey are random elements of the model, while the street graph, routes of travel and traffic parameters are obtained in a deterministic manner. Vehicle speed is dependent on traffic density, and the time needed to cross an intersection depends on the number of waiting vehicles. The route of travel between given start and finish points is determined using Dijkstra’s algorithm, minimising the journey time. The street graph of Wrocław was constructed using data from the Open Street Map website. Identification of parameters and verification of the model were performed using hourly data on traffic volumes at the city’s major intersections in the years 2015–16, obtained from the Intelligent Transport System (ITS). Identification was made of the total number of vehicles travelling in the city at each time of day, a quantity that is difficult to determine by other methods. An accuracy of around 15% was obtained for times between 6.00 and 22.00, while for night-time the verification error exceeded 30%. The model may be used to analyse the impact of planned modifications to the transport system on traffic parameters in the city. It may also serve as a constituent of a larger model for investigating the effect of road transport on atmospheric pollution or for identifying areas at risk of noise pollution.

TripRes

2021 ◽  
Vol 17 (2) ◽  
pp. 1-21
Author(s):  
Xiaolong Xu ◽  
Zijie Fang ◽  
Lianyong Qi ◽  
Xuyun Zhang ◽  
Qiang He ◽  
...  
Keyword(s):  
Traffic Flow ◽  
Discrete Distribution ◽  
Resource Provisioning ◽  
Path Selection ◽  
Urban Traffic ◽  
Traffic Flows ◽  
Multimedia Services ◽  
Traffic Flow Prediction ◽  
The City ◽  
Multimedia Surveillance

The Internet of Vehicles (IoV) connects vehicles, roadside units (RSUs) and other intelligent objects, enabling data sharing among them, thereby improving the efficiency of urban traffic and safety. Currently, collections of multimedia content, generated by multimedia surveillance equipment, vehicles, and so on, are transmitted to edge servers for implementation, because edge computing is a formidable paradigm for accommodating multimedia services with low-latency resource provisioning. However, the uneven or discrete distribution of the traffic flow covered by edge servers negatively affects the service performance (e.g., overload and underload) of edge servers in multimedia IoV systems. Therefore, how to accurately schedule and dynamically reserve proper numbers of resources for multimedia services in edge servers is still challenging. To address this challenge, a traffic flow prediction driven resource reservation method, called TripRes, is developed in this article. Specifically, the city map is divided into different regions, and the edge servers in a region are treated as a “big edge server” to simplify the complex distribution of edge servers. Then, future traffic flows are predicted using the deep spatiotemporal residual network (ST-ResNet), and future traffic flows are used to estimate the amount of multimedia services each region needs to offload to the edge servers. With the number of services to be offloaded in each region, their offloading destinations are determined through latency-sensitive transmission path selection. Finally, the performance of TripRes is evaluated using real-world big data with over 100M multimedia surveillance records from RSUs in Nanjing China.

Strangers in the City: Transmigration from Eastern Europe and its Impact on Berlin and Hamburg 1880–1914

2016 ◽  
Vol 2 (2) ◽  
pp. 223-246
Author(s):  
Tobias Brinkmann
Keyword(s):  
United States ◽  
New York ◽  
Eastern Europe ◽  
The United States ◽  
Urban Traffic ◽  
European Cities ◽  
Massive Growth ◽  
Transit Migration ◽  
The Impact ◽  
The City

This article examines the impact of transit migration from the Russian and Austro-Hungarian Empires on Berlin and Hamburg between 1880 and 1914. Both cities experienced massive growth during the last three decades of the nineteenth century, and both served as major points of passage for Eastern Europeans travelling to (and returning from) the United States. The rising migration from Eastern Europe through Central and Western European cities after 1880 coincided with the need to find adequate solutions to accommodate a rapidly growing number of commuters. The article demonstrates that the isolation of transmigrants in Berlin, Hamburg (and New York) during the 1890s was only partly related to containing contagious disease and ‘undesirable’ migrants. Isolating transmigrants was also a pragmatic response to the increasing pressure on the urban traffic infrastructure.

scholarly journals Simulation of marine vehicles operation in the state of wind and wave conditions

2021 ◽  
pp. 191-199
Author(s):  
А.А. Карпенко
Keyword(s):  
Supply Chain ◽  
Simulation Model ◽  
Transport System ◽  
Wind Wave ◽  
Supply Chain System ◽  
Chain System ◽  
Marine Vehicles ◽  
Marine Transport ◽  
The Impact ◽  
The City

Эксплуатация морского транспорта подвержена влиянию множества факторов, учет которого требует высокой трудоемкости. Как правило, моделирование морских транспортных систем, выступающих в роли связующего звена различных экономических процессов, производится на стадии предпроектной разработки. На этой стадии, помимо прочего, необходимо оценить влияние на проектируемую систему не только детерминированных, но и стохастических процессов. В данной работе описан алгоритм учета влияния ветро-волновых режимов морских участков на эксплуатацию морских транспортных судов. Данный алгоритм реализован на примере модели системы поставок сжиженного природного газа (СПГ) морским транспортом потребителям г. Мурманск. Научной новизной данной работы является комплексный подход к логико-математическому описанию эксплуатации морских транспортных средств. Этот подход включает в себя моделирование эксплуатации судна на базе агентного подхода, моделирование ветро-волновых режимов на основе анализа временных рядов и стохастических экспериментов и определение скорости движения судна на основе эмпирико-статистических формул расчета скорости судна и теории гидродинамики судна. В ходе выполнения данной работы была построена имитационная модель поставок СПГ в г. Мурманск морским транспортом. Результаты прогонов этой модели были верифицированы на основе технико-экономического обоснования АО «ЦНИИМФ». Алгоритм построения имитационной модели, описанный в данной работе, может быть применен для имитационного моделирования морских транспортных систем с различными целями функционирования. Marine transport operation is affected by a lot of factors taking into account of which requires a high laboriousness. In most cases modelling of marine transport operation as a link in various economic processes is performed at the pre-design development stage. By the way, evaluation of the impact of both deterministic and stochastic processes on the designed system is necessary at this stage. Evaluation of transport system efficiency based on pre-formed system of criteria is in progress at this stage. This paper describes an algorithm for modeling the operation of marine vessels taking into account wind-wave regime of sea areas. This algorithm is implemented by the model of liquified natural gas (LNG) supply chain system by marine transport to consumers of the city of Murmansk. Scientific novelty of this paper is a complex approach to logical-mathematical description of marine vehicles exploitation. This approach consists of agent-based simulation of vessel exploitation, modelling of wind-wave regimes by means of time series analysis and stochastic modelling and the speed determination of the vessel movement based on the empirical-statistical formulas for calculating the speed of the vessel and the theory of vessel hydrodynamics. During this research simulation model LNG supply chain system by marine transport to consumers of the city of Murmansk was developed. The results of the model have been verified by the feasibility study performed by CNIIMF JSC. The algorithm for constructing simulation model described in this paper could be implemented in modelling of marine transport system for various purposes.

scholarly journals Spectral Analysis of Traffic Functions in Urban Areas

2015 ◽  
Vol 27 (6) ◽  
pp. 477-484 ◽  
Author(s):  
Florin Nemtanu ◽  
Ilona Madalina Costea ◽  
Catalin Dumitrescu
Keyword(s):  
Spectral Analysis ◽  
Fourier Transform ◽  
Fourier Analysis ◽  
Traffic Flow ◽  
Traffic Control ◽  
Urban Areas ◽  
Urban Traffic ◽  
The Fourier Transform ◽  
The City ◽  
Different Time Scales

The paper is focused on the Fourier transform application in urban traffic analysis and the use of said transform in traffic decomposition. The traffic function is defined as traffic flow generated by different categories of traffic participants. A Fourier analysis was elaborated in terms of identifying the main traffic function components, called traffic sub-functions. This paper presents the results of the method being applied in a real case situation, that is, an intersection in the city of Bucharest where the effect of a bus line was analysed. The analysis was done using different time scales, while three different traffic functions were defined to demonstrate the theoretical effect of the proposed method of analysis. An extension of the method is proposed to be applied in urban areas, especially in the areas covered by predictive traffic control.

scholarly journals The Microsimulation Model for Assessing the Impact of Inbound Traffic Flows for Container Terminals Located near City Centers

2020 ◽  
Vol 12 (22) ◽  
pp. 9478
Author(s):  
Neven Grubisic ◽  
Tomislav Krljan ◽  
Livia Maglić ◽  
Siniša Vilke
Keyword(s):  
Fuel Consumption ◽  
Container Terminal ◽  
Urban Traffic ◽  
Container Terminals ◽  
Critical Parameters ◽  
Traffic Flows ◽  
Traffic Demand ◽  
Gate Time ◽  
The Impact ◽  
The City

The growth of container transport places increasing demand on traffic, especially in situations where container terminals are located near the city centers. The main problem is traffic congestion on networks caused by the integration of Heavy-Duty Vehicles and urban traffic flows. The main objective is to identify the critical traffic parameters which cause negative organizational and environmental impacts on the existing and future traffic demand. A micro-level traffic simulation model was implemented for the testing of the proposed framework-based supply, demand, and control layers. The model was generated and calibrated based on the example of a mid-size Container Terminal “Brajdica” and the City of Rijeka, Croatia. The results indicate that the critical parameters are Queue Length on the approach road to the Container Terminal and the Stop Delay on the main city corridor. High values of these parameters cause negative effects on the environment because of increased fuel consumption and the generation of extra pollution. Due to this problem, a sensitivity analysis of the traffic system performance has been conducted, with a decrement of Terminal Gate Time distribution by 10%. After re-running simulations, the results indicate the impact of subsequent variation in Terminal Gate Time on the decrease of critical parameters, fuel consumption, and vehicle pollution.

Analysis of drivers' characteristics in car-following theory

2014 ◽  
Vol 28 (24) ◽  
pp. 1450191 ◽  
Author(s):  
Geng Zhang ◽  
Di-Hua Sun ◽  
Hui Liu ◽  
Min Zhao
Keyword(s):  
Numerical Simulation ◽  
Traffic Flow ◽  
Mkdv Equation ◽  
Reductive Perturbation Method ◽  
Linear Stability Theory ◽  
Traffic Density ◽  
Car Following ◽  
Car Following Model ◽  
The Stability ◽  
The Impact

In recent years, the influence of drivers' behaviors on traffic flow has attracted considerable attention according to Transportation Cyber Physical Systems. In this paper, an extended car-following model is presented by considering drivers' timid or aggressive characteristics. The impact of drivers' timid or aggressive characteristics on the stability of traffic flow has been analyzed through linear stability theory and nonlinear reductive perturbation method. Numerical simulation shows that the propagating behavior of traffic density waves near the critical point can be described by the kink–antikink soliton of the mKdV equation. The good agreement between the numerical simulation and the analytical results shows that drivers' characteristics play an important role in traffic jamming transition.

scholarly journals Lag Variables in Nitrogen Oxide Concentration Modelling: A Case Study in Wrocław, Poland

Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1293
Author(s):  
Joanna A. Kamińska ◽  
Fernando Jiménez ◽  
Estrella Lucena-Sánchez ◽  
Guido Sciavicco ◽  
Tomasz Turek
Keyword(s):  
Air Quality ◽  
Wind Speed ◽  
Traffic Flow ◽  
Sunshine Duration ◽  
Delayed Effect ◽  
Hourly Data ◽  
Random Forest Models ◽  
Flow Intensity ◽  
Lag Variables ◽  
The Impact

Due to the unwavering interest of both residents and authorities in the air quality of urban agglomerations, we pose the following question in this paper: What impact do current and past meteorological factors and traffic flow intensity have on air quality? What is the impact of lagged variables on the fit of an explanation model, and how do they affect its ability to predict? We focused on NO2 and NOx concentrations, and conducted this research using hourly data from the city of Wrocław (western Poland) from 2015 to 2017; we used multi-objective optimization to determine the optimal delays. It turned out that for both NO2 and NOx, the past values for traffic flow, wind speed, and sunshine duration are more important than the current ones. We built random forest models on each of the pollutants for both the current and past values and discovered that including a lagged variable increases the resulting R2 from 0.51 to 0.56 for NO2 and from 0.46 to 0.52 for NOx. We also analyzed the feature importance in each model, and found that for NO2, a wind speed delay of more than three hours causes a significant decrease, while the importance of relative humidity increases with a seven-hour delay; likewise, wind speed increases the importance for NOx prediction with a two-hour delay. We concluded that, in pollutant concentration modeling, the possibility of a delayed effect of the independent variables should always be considered, because it can significantly increase the performance of the model and suggest unexpected relationships or dependencies.

scholarly journals PUBLIC ADMINISTRATION OF PUBLIC TRANSPORT THROUGH IMPLEMENTATION OF AN INFORMATION AND COMMUNICATION MECHANISM

World Science ◽  
2020 ◽  
Vol 2 (1(53)) ◽  
pp. 16-21
Author(s):  
Davyd Shatirishvili
Keyword(s):  
Public Administration ◽  
Transport System ◽  
Public Transport ◽  
Intelligent Transport System ◽  
Information Communication ◽  
Transport Services ◽  
Communication Mechanism ◽  
The World ◽  
Information And Communication ◽  
The City

The theoretical aspects of application of information and communication mechanism in the field of public transport are defined. The object of study is the field of public land transport services. The purpose of the article is to analyze the world experience in implementing information and communication mechanism and substantiate the need for the use of appropriate technologies in the public administration of the sphere of services in the land public transport in the capital city. The conceptual foundations of creating smart-cities are revealed. The attention is focused on the information and communication technologies as one of the areas of smart-specialization of the city of Kyiv. The world tendencies of introduction of the information-communication or smart-technologies are presented. The problems of functioning of urban transport system are revealed. The feasibility of introducing an intelligent transport system has been proved. The key issues that need to be addressed to improve the current situation in the field of the land public transport in the city of Kyiv are outlined. There is also an emphasis on improving the performance of the carrier-company. The relationship between the information- communication, regulatory, organizational, financial mechanisms is revealed. The need to involve the city dwellers in the development of the management decisions is emphasized.

scholarly journals Modeling daily dynamics of speed and fuel consumption for urban delivery means

2021 ◽  
Vol 9 ◽  
pp. 31-43
Author(s):  
Lidiia Savchenko ◽  
Miroslava Semeriahina ◽  
Irina Shevchenko
Keyword(s):  
Fuel Consumption ◽  
Business Processes ◽  
Road Transport ◽  
Time Of Day ◽  
Traffic Density ◽  
Negative Consequences ◽  
Approximation Accuracy ◽  
Average Speed ◽  
Large Cities ◽  
The City

Road transport is one of the most important elements of the functioning of a modern city. Maneuverability, mobility, speed of delivery of goods and other criteria have provided him with a special and leading place in urban logistics. However, along with the benefits of a developed transport network for society, its progress is accompanied by negative consequences for the environment and the population of the city. High rates of growth in the number of cars, especially in large cities, cause an increase in emissions of harmful products into the atmosphere, which, accordingly, negatively affects the health of the population. Consequently, the problem of environmental pollution in large cities from harmful emissions from vehicles requires an urgent solution. The increase in emissions of harmful substances is affected by an increase in the consumption of fuel materials due to a decrease in speed because of an increase in traffic density in the city. The frequency, duration, prevalence of congestion is increasing along with the urbanization of the population and the increase in the number of cars in cities. The dense development of the central historical districts of the city exacerbates the problem of unhindered passage of individual, public and freight vehicles. In addition, a decrease in the speed of city traffic affects the speed of delivery of goods, correspondence, etc., which negatively affects the speed of business processes, and ultimately worsens the level of logistics services for customers. The purpose of this study is to analyze the current situation in terms of the dynamics of the average speed of the city's traffic flow by hours of the day and to obtain a mathematical model of the dependence of the speed of movement on the consumption of fuel materials for various environmentally friendly means of urban delivery (car, motorcycle, bicycle and pedestrian courier). The research was carried out in two stages. At the first, the study of the dependence of the average speed of movement in the city on the time of day (for all means of city delivery) was carried out. At the second stage, the study of the dependence of the average consumption of fuel materials in the city (which, accordingly, is a function of the speed of movement) on the time of day for motorized urban delivery vehicles was done. In the course of the study, at each stage, an equation of the trend lines was obtained with a sufficient approximation accuracy. In conclusion, the study proposes an algorithm for determining the average speed and average amount of fuel consumption when delivering small consignments in an urban environment using four urban logistics means - a car, a motorcycle, a bicycle, and a pedestrian courier (with the possibility of using public transport). The proposed algorithm can be applied in any delivery conditions in the city.

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