scholarly journals Empirical evidence for a jamming transition in urban traffic

2021 ◽  
Vol 18 (182) ◽  
pp. 20210391
Author(s):  
Erwan Taillanter ◽  
Marc Barthelemy
Keyword(s):  
Spatial Structure ◽  
Empirical Evidence ◽  
Traffic Management ◽  
Reaction Diffusion ◽  
Point Of View ◽  
Urban Traffic ◽  
External Parameter ◽  
Large Cities ◽  
Jamming Transition ◽  
Traffic Jams

Understanding the mechanisms leading to the formation and the propagation of traffic jams in large cities is of crucial importance for urban planning and traffic management. Many studies have already considered the emergence of traffic jams from the point of view of phase transitions, but mostly in simple geometries such as highways for example or in the framework of percolation where an external parameter is driving the transition. More generally, empirical evidence and characterization for a congestion transition in complex road networks are scarce, and here, we use traffic measures for Paris (France) during the period 2014–2018 for testing the existence of a jamming transition at the urban level. In particular, we show that the correlation function of delays due to congestion is a power law (with exponent η ≈ 0.4) combined with an exponential cut-off ξ . This correlation length is shown to diverge during rush hours, pointing to a jamming transition in urban traffic. We also discuss the spatial structure of congestion and identify a core of congested links that participate in most traffic jams and whose structure is specific during rush hours. Finally, we show that the spatial structure of congestion is consistent with a reaction–diffusion picture proposed previously.

Motorist conquest in big cities: The case of Budapest

2008 ◽  
Vol 58 (1) ◽  
pp. 1-28
Author(s):  
Sz. Erhart
Keyword(s):  
Traffic Management ◽  
Travel Demand ◽  
Transport Systems ◽  
Time Loss ◽  
Large Cities ◽  
The Public ◽  
Car Use ◽  
Traffic Jams ◽  
Road Capacity ◽  
Heavy Burden

Economic growth requires well functioning transport systems. The paper deals with the problems associated with ever-increasing car use and traffic jams in Budapest. Car scarcity was the major problem that impeded car use two decades ago which has transformed into road scarcity since then. Road capacity is limited in the Hungarian capital, only the public transport can help to satisfy medium run travel demand of residents. As motorisation and car use grow congestion related time loss, petrol and pollution costs put a heavy burden on Budapest. International experience shows that restrictions on cars can mitigate congestion. In many large cities introduction of road pricing in central areas has become one of the most successful traffic management solutions. Experience in London and Stockholm confirms that citizens support car use restrictions even if they are placed on car use.

scholarly journals Traffic congestion propagation identification method in smart cities

2021 ◽  
Vol 13 (1) ◽  
pp. 45-57
Author(s):  
Attila M. Nagy ◽  
Vilmos Simon
Keyword(s):  
Traffic Congestion ◽  
Traffic Management ◽  
Road Network ◽  
Smart Cities ◽  
Network Data ◽  
Professional Literature ◽  
Large Cities ◽  
Traffic Jam ◽  
The Road ◽  
Traffic Jams

Managing the frequent traffic congestion (traffic jams) of the road networks of large cities is a major challenge for municipal traffic management organizations. In order to manage these situations, it is crucial to understand the processes that lead to congestion and propagation, because the occurrence of a traffic jam does not merely paralyze one street or road, but could spill over onto the whole vicinity (even an entire neighborhood). Solutions can be found in professional literature, but they either oversimplify the problem, or fail to provide a scalable solution. In this article, we describe a new method that not only provides an accurate road network model, but is also a scalable solution for identifying the direction of traffic congestion propagation. Our method was subjected to a detailed performance analysis, which was based on real road network data. According to testing, our method outperforms the ones that have been used to date.

scholarly journals Automated Planning for Urban Traffic Management

2017 ◽  
Author(s):  
Thomas L. McCluskey ◽  
Mauro Vallati ◽  
Santiago Franco
Keyword(s):  
Air Quality ◽  
Traffic Management ◽  
Road Traffic ◽  
Automated Planning ◽  
Road Transport ◽  
Urban Traffic ◽  
Traffic Emissions ◽  
Transport Infrastructure ◽  
Large Cities ◽  
Road Traffic Emissions

The global growth in urbanisation increases the demand for services including road transport infrastructure, presenting challenges in terms of mobility. Optimising the exploitation of urban road network, while attempting to minimise the effects of traffic emissions, is a great challenge. SimplyfAI was a UK research council grant funded project which was aimed towards solving air quality problems caused by road traffic emissions. Large cities such as Manchester struggle to meet air quality limits as the range of available traffic management devices is limited. In the study, we investigated the application of linked data to enrich environmental and traffic data feeds, and we used this with automated planning tools to enable traffic to be managed at a region level. The management will have the aim of avoiding air pollution problems before they occur. This demo focuses on the planning component, and in particular the engineering and validation aspects, that were pivotal for the success of the project.

scholarly journals Can Negative Travel Habits Hinder Positive Travel Behavioural Change under Beijing Vehicle Restrictions?

2020 ◽  
Vol 32 (5) ◽  
pp. 691-709
Author(s):  
Xiao Dong ◽  
Ruoya Wang ◽  
Yaodong Zhou
Keyword(s):  
Traffic Management ◽  
Structural Equation ◽  
Rapid Development ◽  
Behavioural Change ◽  
Travel Behaviour ◽  
Urban Traffic ◽  
Mediating Effect ◽  
Personal Lives ◽  
Large Cities ◽  
The Impact

Given the rapid development of large cities, the residents faced with pressure both at work and in their personal lives tend to solidify their choice of transport modes and form personal travel habits, which in turn leads to higher requirements for urban traffic management. Based on the modified Theory of Planned Behaviour, the structural equation method is employed to explore people’s travel behaviour. It is found that policy attitude, perceived behaviour control, and subjective norms comprehensively affect the residents’ travel intentions under the Vehicle Restrictions in place in Beijing. The residents without private cars display a stronger intention to change their travel choices under the policies. When considering the mediating effect of travel habits between travel intention and travel choice, the impact of the restrictive policies is weakened. Compared with lower-income people, those with higher incomes demonstrate more stable travel habits in response to the effects of the restrictions. The higher the income, the greater the dependence on private cars exhibited by the residents. To summarize, people’s travel habits weaken to some extent the effects of the restrictive policies. Such policies should be created with the explicit aim of gradually changing the people’s habits.

Remembering From-the-Outside

2018 ◽  
Author(s):  
Christopher McCarroll
Keyword(s):  
Empirical Evidence ◽  
Point Of View ◽  
Philosophical Analysis ◽  
Visual Perspective ◽  
Observer Perspective ◽  
The Status ◽  
Key Issues ◽  
Way Of Thinking

This chapter sets out some key issues related to a philosophical analysis of point of view in memory. It does so by looking at examples of psychological, philosophical, and literary accounts of the phenomenon, as well as examples of the author’s own observer perspective memories. The chapter provides an overview of some of the empirical evidence related to visual perspective in memory. Despite these consistent empirical findings, however, a number of doubts and misconceptions about remembering from-the-outside still linger, especially concerning the status of observer perspectives in memory. This chapter outlines some of the skepticism to the possibility of remembering from-the-outside and points to a possible diagnosis of why such skepticism arises. This chapter points to a way of thinking about memory—to be developed through the course of the book—which eases the worries about remembering from-the-outside.

scholarly journals European Regional Inequalities: The Other Face of Development

2017 ◽  
Vol 9 (4) ◽  
pp. 163
Author(s):  
Celeste Perrucchini ◽  
Hiroshi Ito
Keyword(s):  
European Union ◽  
Empirical Evidence ◽  
Capita Income ◽  
Relevant Literature ◽  
Point Of View ◽  
The European Union ◽  
Per Capita Income ◽  
Member States ◽  
Eu Member States ◽  
Per Capita

Empirical evidence suggests an overall convergence in terms of GDP and per capita income occurring among the European Union (EU) Member States. Nevertheless, economic inequalities have been increasing at the regional level within European Union countries. Through the review of relevant literature, this study analyzes the increasing inequalities from an economical point of view, focusing on Italy and the UK as examples. First, a general overlook of the empirical evidence of the GDP and per capita income at national and sub-national levels will be presented. Second, an explanation of the possible causes of the results will be proposed through the use of economical and sociological theories. The findings of this research might uncover the relative inefficacy of EU Cohesion policies and point towards the necessity for deeper and more thoughtful measures to continue the convergence of Member States while preserving internal equilibria. This paper ends with discussions for the future directions of the EU.

scholarly journals Spatio-Temporal Visual Analysis for Urban Traffic Characters Based on Video Surveillance Camera Data

2021 ◽  
Vol 10 (3) ◽  
pp. 177
Author(s):  
Haochen Zou ◽  
Keyan Cao ◽  
Chong Jiang
Keyword(s):  
Video Surveillance ◽  
Traffic Management ◽  
Visual Analysis ◽  
Urban Traffic ◽  
License Plate ◽  
Road Vehicle ◽  
Urban Road ◽  
Surveillance Camera ◽  
Vehicle Density ◽  
Spatio Temporal

Urban road traffic spatio-temporal characters reflect how citizens move and how goods are transported, which is crucial for trip planning, traffic management, and urban design. Video surveillance camera plays an important role in intelligent transport systems (ITS) for recognizing license plate numbers. This paper proposes a spatio-temporal visualization method to discover urban road vehicle density, city-wide regional vehicle density, and hot routes using license plate number data recorded by video surveillance cameras. To improve the accuracy of the visualization effect, during data analysis and processing, this paper utilized Internet crawler technology and adopted an outlier detection algorithm based on the Dixon detection method. In the design of the visualization map, this paper established an urban road vehicle traffic index to intuitively and quantitatively reveal the traffic operation situation of the area. To verify the feasibility of the method, an experiment in Guiyang on data from road video surveillance camera system was conducted. Multiple urban traffic spatial and temporal characters are recognized concisely and efficiently from three visualization maps. The results show the satisfactory performance of the proposed framework in terms of visual analysis, which will facilitate traffic management and operation.

scholarly journals Interdisciplinary Evaluation of Intersection Performances—A Microsimulation-Based MCDA

2021 ◽  
Vol 13 (4) ◽  
pp. 1859
Author(s):  
Kadir Diler Alemdar ◽  
Ahmet Tortum ◽  
Ömer Kaya ◽  
Ahmet Atalay
Keyword(s):  
Traffic Engineering ◽  
Traffic Management ◽  
Evaluation Criteria ◽  
Urban Traffic ◽  
Suitable Alternative ◽  
Order Preference ◽  
Energy Environment ◽  
Vehicle Delay ◽  
Hierarchy Process ◽  
Co Emission

Intersections are the most important regions in terms of urban traffic management. The intersection areas on the corridor should be analyzed together for consistency in traffic engineering. To do so, three intersections on the Vatan Street corridor in İstanbul, the most crowded city of Turkey, were examined. Various geometric and signal designs were performed for intersections and the most suitable corridor design was analyzed. The corridor designs were modeled with the PTV VISSIM microsimulation software. The most suitable corridor design was evaluated by using the results obtained from the microsimulation via analytical hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS) from multi criteria decision analysis (MCDA) methods. The evaluation criteria in the study are vehicle delay, queue length, stopped delay, stops, travel time, vehicle safety, CO emission, fuel consumption, and construction cost. As a result, the current and the most suitable alternative corridors were compared according to the comparison parameters and up to 80% improvements were observed. Thus, some advantages were obtained in terms of energy, environment, time, and cost.

Bilateral Treaties and The Most-Favored-Nation Clause: The Myth of Trade Liberalization in the Nineteenth Century

2008 ◽  
Vol 60 (2) ◽  
pp. 147-188 ◽  
Author(s):  
Olivier Accominotti ◽  
Marc Flandreau
Keyword(s):  
International Trade ◽  
Trade Liberalization ◽  
Empirical Evidence ◽  
Trade Agreement ◽  
Trade Agreements ◽  
Point Of View ◽  
Most Favored Nation ◽  
The World ◽  
Most Favored Nation Clause ◽  
Bilateral Treaties

Textbook accounts of the Anglo-French trade agreement of 1860 argue that it heralded the beginning of a liberal trading order. This alleged success holds much interest from a modern policy point of view, for it rested on bilateral negotiations and most-favored-nation clauses. With the help of new data on international trade (the RICardo database), the authors provide empirical evidence and find that the treaty and subsequent network of MFN trade agreements coincided with the end of a period of unilateral liberalization across the world. They also find that it did not contribute to expanding trade at all. This is contrary to a deeply rooted belief among economists, economic historians, and political scientists. The authors draw a number of policy lessons that run counter to the conventional wisdom and raise skepticism toward the ability of bilateralism and MFN arrangements to promote trade liberalization.

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