MODELING TRAFFIC FLUCTUATIONS AND CONGESTION ON A ROAD NETWORK

2015 ◽  
Vol 18 (03n04) ◽  
pp. 1550009 ◽  
Author(s):  
E. ANDREOTTI ◽  
A. BAZZANI ◽  
S. RAMBALDI ◽  
N. GUGLIELMI ◽  
P. FREGUGLIA
Keyword(s):  
Numerical Simulations ◽  
Road Network ◽  
Statistical Physics ◽  
Transition Probabilities ◽  
Traffic Load ◽  
Flow Density ◽  
The Road ◽  
Random Transition ◽  
Emilia Romagna Region ◽  
On The Road

Statistical mechanics points out as fluctuations have a relevant role for systems near critical points. We study the effect of traffic fluctuations and the transition to congested states for a stochastic dynamical model of traffic on a road network. The model simulates a finite population that moves from one road to another according to random transition probabilities. In such a way, we mimic the traffic fluctuations due to the granular feature of traffic and the dynamics at the crossing points. Then the amplitude of traffic flow fluctuations is proportional to the average flow as suggested by empirical observations. Assuming a parabolic shaped flow-density relation, there exists an unstable critical point for the road dynamics and the system can perform a phase transition to a congested state, where some roads reach their maximal capacity. We apply a statistical physics approach to study the onset congestion and we characterize analytically the relation between the fluctuations amplitude and the appearance of congested nodes. We verify the results by means of numerical simulations on a Manhattan-like road network. Moreover we point out the existence of oscillating regimes, where traffic oscillations back propagate on the road network, whose onset depend sensitively from the traffic fluctuations and that have a strong influence on the hysteresis cycles of the systems when the traffic load is modulated. The comparison between the numerical simulations and the empirical traffic data recorded by an inductive-loop traffic detector system (MTS system) on the county roads of the Emilia Romagna region in Italy is shortly discussed.

scholarly journals Roads at risk – traffic detours from debris flows in southern Norway

2014 ◽  
Vol 2 (10) ◽  
pp. 6623-6651 ◽  
Author(s):  
N. K. Meyer ◽  
W. Schwanghart ◽  
O. Korup ◽  
F. Nadim
Keyword(s):  
Debris Flows ◽  
Road Network ◽  
Traffic Load ◽  
Extreme Weather Events ◽  
Northwestern Part ◽  
Link Failure ◽  
The Road ◽  
On The Road ◽  
Southern Norway ◽  
The Impact

Abstract. Globalization and interregional exchange of people, goods, and services has boosted the importance of and reliance on all kinds of transport networks. The linear structure of road networks is especially sensitive to natural hazards. In southern Norway, steep topography and extreme weather events promote frequent traffic disruption caused by debris flows. Topographic susceptibility and trigger frequency maps serve as input into a hazard appraisal at the scale of first-order catchments to quantify the impact of debris flows on the road network in terms of a failure likelihood of each link connecting two network vertices, e.g., road junctions. We compute total additional traffic loads as a function of traffic volume and excess distance, i.e. the extra length of an alternative path connecting two previously disrupted network vertices using a shortest-path algorithm. Our risk metric of link failure is the total additional annual traffic load expressed as vehicle kilometers because of debris-flow related road closures. We present two scenarios demonstrating the impact of debris flows on the road network, and quantify the associated path failure likelihood between major cities in southern Norway. The scenarios indicate that major routes crossing the central and northwestern part of the study area are associated with high link failure risk. Yet options for detours on major routes are manifold, and incur only little additional costs provided that drivers are sufficiently well informed about road closures. Our risk estimates may be of importance to road network managers and transport companies relying of speedy delivery of services and goods.

scholarly journals Roads at risk: traffic detours from debris flows in southern Norway

2015 ◽  
Vol 15 (5) ◽  
pp. 985-995 ◽  
Author(s):  
N. K. Meyer ◽  
W. Schwanghart ◽  
O. Korup ◽  
F. Nadim
Keyword(s):  
Debris Flows ◽  
Road Network ◽  
Linear Structure ◽  
Traffic Load ◽  
Extreme Weather Events ◽  
Link Failure ◽  
The Road ◽  
On The Road ◽  
Southern Norway ◽  
The Impact

Abstract. Globalisation and interregional exchange of people, goods, and services has boosted the importance of and reliance on all kinds of transport networks. The linear structure of road networks is especially sensitive to natural hazards. In southern Norway, steep topography and extreme weather events promote frequent traffic disruption caused by debris flows. Topographic susceptibility and trigger frequency maps serve as input into a hazard appraisal at the scale of first-order catchments to quantify the impact of debris flows on the road network in terms of a failure likelihood of each link connecting two network vertices, e.g. road junctions. We compute total additional traffic loads as a function of traffic volume and excess distance, i.e. the extra length of an alternative path connecting two previously disrupted network vertices using a shortest-path algorithm. Our risk metric of link failure is the total additional annual traffic load, expressed as vehicle kilometres, because of debris-flow-related road closures. We present two scenarios demonstrating the impact of debris flows on the road network and quantify the associated path-failure likelihood between major cities in southern Norway. The scenarios indicate that major routes crossing the central and north-western part of the study area are associated with high link-failure risk. Yet options for detours on major routes are manifold and incur only little additional costs provided that drivers are sufficiently well informed about road closures. Our risk estimates may be of importance to road network managers and transport companies relying on speedy delivery of services and goods.

scholarly journals Politics, industry, and tourism: The conceptual construction of the blue highway

2020 ◽  
pp. 002252662097950
Author(s):  
Fredrik Bertilsson
Keyword(s):  
Road Network ◽  
Power Plants ◽  
Community Building ◽  
Atlantic Coast ◽  
Political Agenda ◽  
The Road ◽  
Conceptual Construction ◽  
On The Road ◽  
Post War

This article contributes to the research on the expansion of the Swedish post-war road network by illuminating the role of tourism in addition to political and industrial agendas. Specifically, it examines the “conceptual construction” of the Blue Highway, which currently stretches from the Atlantic Coast of Norway, traverses through Sweden and Finland, and enters into Russia. The focus is on Swedish governmental reports and national press between the 1950s and the 1970s. The article identifies three overlapping meanings attached to the Blue Highway: a political agenda of improving the relationships between the Nordic countries, industrial interests, and tourism. Political ambitions of Nordic community building were clearly pronounced at the onset of the project. Industrial actors depended on the road for the building of power plants and dams. The road became gradually more connected with the view of tourism as the motor of regional development.

scholarly journals THE PENETRATION OF ENGINEERING BY ECONOMICS: McFADDEN AND THE TRANSFORMATION OF ROAD DEMAND ESTIMATION

2021 ◽  
Vol 43 (2) ◽  
pp. 262-278
Author(s):  
Ariane Dupont-Kieffer ◽  
Sylvie Rivot ◽  
Jean-Loup Madre
Keyword(s):  
Road Network ◽  
Road Construction ◽  
Demand Estimation ◽  
Demand Modeling ◽  
The Road ◽  
Collective Decisions ◽  
The Face ◽  
Decision Making Processes ◽  
On The Road ◽  
The 1960S

The golden age of road demand modeling began in the 1950s and flourished in the 1960s in the face of major road construction needs. These macro models, as well as the econometrics and the data to be processed, were provided mainly by engineers. A division of tasks can be observed between the engineers in charge of estimating the flows within the network and the transport economists in charge of managing these flows once they are on the road network. Yet the inability to explain their decision-making processes and individual drives gave some room to economists to introduce economic analysis, so as to better understand individual or collective decisions between transport alternatives. Economists, in particular Daniel McFadden, began to offer methods to improve the measure of utility linked to transport and to inform the engineering approach. This paper explores the challenges to the boundaries between economics and engineering in road demand analysis.

scholarly journals Measures to optimize traffic and the environment. Calculations of environmental safety on a given section of the Rostov-on-Don road network

2020 ◽  
pp. 68-77
Author(s):  
R. S. Durov ◽  
◽  
E. V. Varnakova ◽  
K. O. Kobzev ◽  
◽  
...  
Keyword(s):  
Road Network ◽  
Road Transport ◽  
Environmental Safety ◽  
Environmental Indicators ◽  
Nox Emissions ◽  
The Road ◽  
Before And After ◽  
Reduce Emissions ◽  
On The Road ◽  
State Of The Environment

Introduction. One of the most pressing socio-economic problems is the state of the environment, which affects the living conditions of many people. The article deals with the problem areas of the intersection of 20-ya Liniya street – Sholokhov Avenue in Rostov-on-Don. Problem Statement. The purpose of this paper is to improve environmental safety at the intersection of 20-ya Liniya street – Sholokhov Avenue in Rostov-on-Don by reducing emissions from road transport through the proposed measures to reorganize traffic on this section of the road network. Theoretical Part. The article provides an assessment of environmental and road safety on the road network section before applying the proposed measures. The measures are listed and justified that would help improve the conditions for road transport at the selected intersection and reduce emissions from road transport, which would improve environmental safety. The calculation of environmental indicators was made after the proposed measures to reduce NOx emissions by cars. Conclusion. The article analyzes the environmental indicators before and after the events, and then compares them. Based on the analysis and calculations, it is determined how much the proposed measures to optimize traffic will help reduce NOx emissions by cars.

scholarly journals Two-Layer Routing for High-Voltage Powerline Inspection by Cooperated Ground Vehicle and Drone

2019 ◽  
Author(s):  
Yao Liu ◽  
Jianmai Shi ◽  
Zhong Liu ◽  
Jincai Huang ◽  
Tianren Zhou
Keyword(s):  
High Voltage ◽  
Road Network ◽  
Inspection System ◽  
Large Area ◽  
Technical Improvement ◽  
Routing Problem ◽  
Ground Vehicle ◽  
The Road ◽  
Battery Capacity ◽  
On The Road

A novel high-voltage powerline inspection system is investigated, which consists of the cooperated ground vehicle and drone. The ground vehicle acts as a mobile platform that can launch and recycle the drone, while the drone can fly over the powerline for inspection within limited endurance. This inspection system enables the drone to inspect powerline networks in a very large area. Both vehicle’ route in the road network and drone’s routes along the powerline network have to be optimized for improving the inspection efficiency, which generates a new two-layer point-arc routing problem. Two constructive heuristics are designed based on “Cluster First, Rank Second” and “Rank First, Split Second”. Then local search strategies are developed to further improve the quality of the solution. To test the performance of the proposed algorithms, practical cases with different-scale are designed based on the road network and powerline network of Ji’an, China. Sensitivity analysis on the parameters related with the drone’s inspection speed and battery capacity is conducted. Computational results indicate that technical improvement on the inspection sensor is more important for the cooperated ground vehicle and drone system.

scholarly journals Analysis of Traffic Evolution on Road Networks of a Roundabout

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Tolesa Hundesa Muleta ◽  
Legesse Lemecha Obsu
Keyword(s):  
Traffic Congestion ◽  
Road Network ◽  
Road Networks ◽  
Point Of View ◽  
Traffic Dynamics ◽  
Demand And Supply ◽  
The Road ◽  
On The Road ◽  
Detailed Mathematical Analysis ◽  
Control Traffic

In this paper, the analyses of traffic evolution on the road network of a roundabout having three entrances and three exiting legs are conducted from macroscopic point of view. The road networks of roundabouts are modeled as a merging and diverging types 1×2 and 2×1 junctions. To study traffic evolution at junction, two cases have been considered, namely, demand and supply limited cases. In each case, detailed mathematical analysis and numerical tests have been presented. The analysis in the case of demand limited showed that rarefaction wave fills the portion of the road network in time. In the contrary, in supply limited case, traffic congestion occurs at merging junctions and shock wave propagating back results in reducing the performance of a roundabout to control traffic dynamics. Also, we illustrate density and flux profiles versus space discretization at different time steps via numerical simulation with the help of Godunov scheme.

scholarly journals STUDY ON ESTIMATION OF PAVEMENT CONDITIONS ON THE ROAD NETWORK USING SAMPLING THEORY

2015 ◽  
Vol 70 (3) ◽  
pp. I_165-I_171
Author(s):  
Yuichiro KANEKO ◽  
Kazuhisa OGIWARA ◽  
Hisashi TAKAGI ◽  
Katsuhiro ITO ◽  
Tetsuya MATSUSHIMA
Keyword(s):  
Road Network ◽  
Sampling Theory ◽  
The Road ◽  
On The Road
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