scholarly journals Optimization of Evacuation and Walking-Home Routes from Osaka City After a Nankai Megathrust Earthquake Using Road Network Big Data

2021 ◽  
pp. 369-389
Author(s):  
Atsushi Takizawa ◽  
Yutaka Kawagishi

AbstractWhen a disaster such as a large earthquake occurs, the resulting breakdown in public transportation leaves urban areas with many people who are struggling to return home. With people from various surrounding areas gathered in the city, unusually heavy congestion may occur on the roads when the commuters start to return home all at once on foot. In this chapter, it is assumed that a large earthquake caused by the Nankai Trough occurs at 2 p.m. on a weekday in Osaka City, where there are many commuters. We then assume a scenario in which evacuation from a resulting tsunami is carried out in the flooded area and people return home on foot in the other areas. At this time, evacuation and returning-home routes with the shortest possible travel times are obtained by solving the evacuation planning problem. However, the road network big data for Osaka City make such optimization difficult. Therefore, we propose methods for simplifying the large network while keeping those properties necessary for solving the optimization problem and then recovering the network. The obtained routes are then verified by large-scale pedestrian simulation, and the effect of the optimization is verified.

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Minzhi Chen ◽  
Fan Wu ◽  
Min Yin ◽  
Jiangang Xu

Planning of road networks is fundamental for public transportation. The impact of road network density on public transportation has been extensively studied, but few studies in this regard involved evaluation indicators for connectivity and layout of road networks. With 29 cities in China as the study cases, this paper quantifies the layout structure of the road network based on the network’s betweenness centralization and establishes a multivariate linear regression model to perform regression of the logarithm of the frequency of per capita public transportation on betweenness centralization. It is found in the present work that there is a significant correlation between the layout structure of an urban road network and the residents’ utilization degree of public transportation. A greater betweenness centralization of the urban road network, namely a more centralized road network, means a higher frequency of per capita public transportation of urban residents and a higher degree of the residents’ utilization of public transportation. In the development of public transportation, centralized and axial-shaped layout structures of road networks can be promoted to improve the utilization of public transportation.


2018 ◽  
Vol 11 (1) ◽  
pp. 1 ◽  
Author(s):  
Cristiano Silva ◽  
Lucas Silva ◽  
Leonardo Santos ◽  
João Sarubbi ◽  
Andreas Pitsillides

Over the past few decades, the growth of the urban population has been remarkable. Nowadays, 50% of the population lives in urban areas, and forecasts point that by 2050 this number will reach 70%. Today, 64% of all travel made is within urban environments and the total amount of urban kilometers traveled is expected to triple by 2050. Thus, seeking novel solutions for urban mobility becomes paramount for 21st century society. In this work, we discuss the performance of vehicular networks. We consider the metric Delta Network. The Delta Network characterizes the connectivity of the vehicular network through the percentage of travel time in which vehicles are connected to roadside units. This article reviews the concept of the Delta Network and extends its study through the presentation of a general heuristic based on the definition of scores to identify the areas of the road network that should receive coverage. After defining the general heuristic, we show how small changes in the score computation can generate very distinct (and interesting) patterns of coverage, each one suited to a given scenario. In order to exemplify such behavior, we propose three deployment strategies based on simply changing the computation of scores. We compare the proposed strategies to the intuitive strategy of allocating communication units at the most popular zones of the road network. Experiments show that the strategies derived from the general heuristic provide higher coverage than the intuitive strategy when using the same number of communication devices. Moreover, the resulting pattern of coverage is very interesting, with roadside units deployed a circle pattern around the traffic epicenter.


2005 ◽  
Vol 58 (2) ◽  
pp. 273-282 ◽  
Author(s):  
Wu Chen ◽  
Zhilin Li ◽  
Meng Yu ◽  
Yongqi Chen

Map matching has been widely applied in car navigation systems as an efficient method to display the location of vehicles on maps. Various map-matching algorithms have been proposed. Inevitably, the correctness of the map matching is closely related to the accuracy of positioning sensors, such as GPS or Dead Reckoning (DR), and the complexity of the road network and map, especially in urban areas where the GPS signal may be constantly blocked by buildings and the road network is complicated. The existing map matching algorithms cannot resolve the positioning problems under all circumstances. They sometimes give the wrong position estimates of the car on road; the result is called mismatching. In order to improve the quality of map matching, a deep understand of the accuracy of sensor errors on mismatching is important. This paper analyses various factors that may affect the quality of map matching based on extensive tests in Hong Kong. Suggestions to improve the success rate of map matching are also provided.


Author(s):  
A. Al-jaberi

Transport is a link between territories with different types of land use in urban areas. At the same time, the improved accessibility associated with the transport network can lead to increased segregation and a change in land use. The article analyzes the road network of the Najaf and Kufa cities, Najaf province, Iraq, in order to identify the spatial classification of roads and streets. Based on the analysis, three main types of roads and streets are identified with respect to their structural features and characteristics: regional, city and district. The dependence of the typology and location of transit-oriented zones on the classification of the road network is indicated. In the process of analyzing the study area, the most optimal points for the practice of transit-oriented development (TOD) are identified, the territories most favorable for the location of transit-oriented zones of regional, city and district significance are introduced, the main characteristics of these zones are given. In order to reach goals, this article includes the collection of data and the creation of a database for land use applying a geographic information systems (GIS) environment. The result of the spatial analysis are five regional nodes, six urban nodes and seven district nodes


Author(s):  
Mustapha Kabrane ◽  
Salah-ddine Krit ◽  
Lahoucine El Maimouni

In large cities, the increasing number of vehicles private, society, merchandise, and public transport, has led to traffic congestion. Users spend much of their time in endless traffic congestion. To solve this problem, several solutions can be envisaged. The interest is focused on the  system of road signs: The use of a road infrastructure is controlled by a traffic light controller, so it is a matter of knowing how to make the best use of the controls of this system (traffic lights) so as to make traffic more fluid. The values of the commands computed by the controller are determined by an algorithm which is ultimately, only solves a mathematical model representing the problem to be solved. The objective is to make a study and then the comparison on the optimization techniques based on artificial intelligence1 to intelligently route vehicle traffic. These techniques make it possible to minimize a certain function expressing the congestion of the road network. It can be a function, the length of the queue at intersections, the average waiting time, also the total number of vehicles waiting at the intersection


2020 ◽  
Vol 6 (01) ◽  
pp. 29
Author(s):  
Hendra Hendrawan

The Peak Hour Factor (PHF) is an important variable for determining road capacity. The value of PHF will vary greatly depending on location characteristics and classification of road functions. This study aims to obtain the estimated value of PHF in the urban road network system with variations in the classification of functions and types of roads. In addition this study also aims to obtain a method of approaching the PHF value near to fluctuations in traffic flow which has limited resources for surveys based on the duration specified in the traffic survey guidelines in Indonesia. The method used is descriptive statistical analysis and parametric test using Independent T sample test. The PHF is calculated based on Fixed Hourly Interval and Moving Hourly Interval and their inverse. The results of the study show the value of PHF in the road network system in urban areas for variations function and type of road that is in the range of 0.79 to 0.98 with an average of 0.91. Other findings show that the inverse method of Moving Hourly Interval can be used as an approach to obtain the PHF value under conditions of resource constraints


2021 ◽  
Vol 10 (4) ◽  
pp. 248
Author(s):  
Nicolas Tempelmeier ◽  
Udo Feuerhake ◽  
Oskar Wage ◽  
Elena Demidova

The discovery of spatio-temporal dependencies within urban road networks that cause Recurrent Congestion (RC) patterns is crucial for numerous real-world applications, including urban planning and the scheduling of public transportation services. While most existing studies investigate temporal patterns of RC phenomena, the influence of the road network topology on RC is often overlooked. This article proposes the ST-Discovery algorithm, a novel unsupervised spatio-temporal data mining algorithm that facilitates effective data-driven discovery of RC dependencies induced by the road network topology using real-world traffic data. We factor out regularly reoccurring traffic phenomena, such as rush hours, mainly induced by the daytime, by modelling and systematically exploiting temporal traffic load outliers. We present an algorithm that first constructs connected subgraphs of the road network based on the traffic speed outliers. Second, the algorithm identifies pairs of subgraphs that indicate spatio-temporal correlations in their traffic load behaviour to identify topological dependencies within the road network. Finally, we rank the identified subgraph pairs based on the dependency score determined by our algorithm. Our experimental results demonstrate that ST-Discovery can effectively reveal topological dependencies in urban road networks.


2021 ◽  
Vol 13 (1) ◽  
pp. 372
Author(s):  
Yadan Yan ◽  
Tianzhao Guo ◽  
Dongwei Wang

Accessibility is important for road network planning and design, especially the accessibility of freeway entrances and exits, which reflects the convenience of travelers using freeways and the rationality of the connection between urban roads and freeways. Based on the path information of navigation map software, a new comprehensive travel impedance model to dynamically analyze the accessibility of freeway entrances and exits was proposed. The dynamic accessibility of freeway entrances and exits in Zhengzhou was studied using the proposed comprehensive impedance model, and the calculation results were analyzed. The accessibility of freeway entrances and exits is characterized by dynamic changes; the accessibility during the off-peak evening period is the highest, while that during the morning peak period and evening peak period is lower. The results of the comprehensive impedance model are roughly consistent with reality. From a location perspective, regardless of the period of time, the accessibility of freeway entrances and exits in the central and surrounding areas of Zhengzhou is always at a lower level, and during the off-peak afternoon period, the accessibility of the eastern part of the city is notably higher than that of the western part. Additionally, the accessibility of freeway entrances and exits is closely related to the traffic status of the road network and the characteristics of regional land use. The information can provide feedback for planning road networks and provide a reference for road network planning and traffic facility design.


Author(s):  
Victoria Bitykova ◽  
Nikita Mozgunov

The main discussion is about methods for assessing the intensity of traffic flows using geoinformation technologies. The intensity of traffic flows is one of the key indicators that determine the emission from transport in urban areas. In Russia, the growth in the volume and share of motor transport in pollution is increasing under the influence of an increase in the number of cars. This is most obvious examples of it are regions of the Central Federal District, but in the regional centers, under the influence of the improvement in the structure of the vehicle park, the growth of pollution is much slower, and in Moscow it has practically stabilized. At the local level, the determining factor of road traffic pollution is the change in the building density and the transport-planning structure. The collection and calculation of indicators that give an idea of the spatial differentiation of emissions from road transport is a very time-consuming stage of the study. The most common method of obtaining information on the transport and environmental situation in the city is directly field data collection. However, this method is quite time consuming for research. In conditions when the transport infrastructure is developing rapidly, the speed of field observations does not allow promptly updating information on changes in the traffic load of the road network and, as a result, assessing the current ecological situation in the territory. As an alternative to the traditional collection of information, modern sources of geoinformation data can be used. The services, originally developed to provide operational monitoring of the traffic situation and the construction of optimal routes, can also serve as a source of data for models for assessing the intensity of traffic load in environmental studies. The proposed technique has been tested at the level of districts and administrative districts of Moscow. The results obtained are compared with control field observations. The relatively low measurement error when using data from information systems is compensated by the possibility of more efficiently obtaining information about the traffic load on the sections of the road network.


2021 ◽  
Vol 34 (01) ◽  
pp. 103-111
Author(s):  
Arkady V. Zakharov ◽  
Tatiana R. Zabalueva

Broadband highways are being built in major cities around the world to combat traffic congestion. At the same time, existing buildings are demolished or powerful overpasses are raised above them. However, it often turns out that newly created highways quickly exhaust their capacity, and traffic jams are formed on them again. This situation indicates that increasing the capacity of the highway does not solve the problem of traffic jams, but often aggravates it, since as a result of this increase, even more cars are drawn to the highway from adjacent territories, often exceeding their current capacity. At the same time, the streets in the surrounding areas are empty and their potential is not used to the full extent. This situation has arisen due to the disruption of the city road network by lengthy obstacles in the form of ravines, rivers, floodplains of small rivers, and railways. This situation can be corrected by "stitching" the streets over the gaps by building bridges and overpasses with a capacity corresponding to the capacity of the "stitched" streets. Most of the gaps fall on relatively small streets, which approach the banks of fairly wide floodplains of small rivers and streams, and this makes it advisable to build mainly small (with a span of 20-25 m) and relatively inexpensive bridges, with the number of spans sufficient to cover the floodplain and reach the levels of road surfaces of connected streets. There will be several hundred such bridges over the river barriers in a large city, for example, Moscow, and several hundred more, taking into account the required number of them over the railways, and in the end, about a thousand. It is proposed to erect bridge buildings instead of simple road bridges. Such structures combine two city functions; the first of them is transport, the second is public, residential, or economic, depending on the needs of the city and the environmental situation at the construction site. An important requirement for the second function is a quick return on the financial assets invested in the construction and income from the operation of the building acceptable to the investor. The bridge part of a bridge building should become the property of the city.


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