IATSS Review
Online ISSN : 2433-4537
Print ISSN : 0386-1104
Current issue
Functional Improvement and Evolution of Deteriorating Transportation Infrastructure
Showing 1-9 articles out of 9 articles from the selected issue
Opinions
Special Supplement : Functional Improvement and Evolution of Deteriorating Transportation Infrastructure
Introduction
Review
  • Kazuhiro OHTA
    2020 Volume 44 Issue 3 Pages 160-169
    Published: February 29, 2020
    Released: February 29, 2020
    JOURNALS FREE ACCESS

    This survey examines changes in public policy to address deterioration of transportation social capital, with special focus on road facilities. Public measures to deal with infrastructure deterioration comprise three levels. Systematic measures by the nation as a whole have commenced, triggered by the Sasago Tunnel accident on December 2, 2012. Measures by the Ministry of Land, Infrastructure, Transport and Tourism were formulated immediately before the accident. The ministry has previously made efforts to address deterioration of road facilities, and led the drafting of countermeasure guidelines for the nation as a whole. One 5-year PDCA cycle has been carried out, and it appears that a system has been fully put in place for measures to address deterioration of road facilities. However, two issues remain: securing funding and infrastructure degeneration.

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Review
  • Masaki NAKAHIGASHI
    2020 Volume 44 Issue 3 Pages 170-177
    Published: February 29, 2020
    Released: February 29, 2020
    JOURNALS FREE ACCESS

    This study uses stock data on infrastructure in Japan from “Measuring Infrastructure in Japan 2017”, released by the Japanese Cabinet Office, to elucidate the current situation of aging infrastructure in Japan. An aging indicator based on stock data shows that there are differences in aging between infrastructure sectors, but almost no differences in degree of aging due to city scale. Additionally, the results show that aging has occurred in all infrastructure sectors, and that there is inadequate commitment of resources to maintain infrastructure quality.

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Information
  • Atsushi FUKUSHIMA
    2020 Volume 44 Issue 3 Pages 178-187
    Published: February 29, 2020
    Released: February 29, 2020
    JOURNALS FREE ACCESS

    Expressway managed by NEXCO Central Nippon runs a total distance of approximately 2,100 km and around 60% of the expressway has been open for 30 years or more. In particular, all routes on the Tomei Expressway and Meishin Expressway, which link the east-west axis of the Greater Tokyo Area, the Tokai Area, and the Kansai Area, have been open for 50 years. These two expressways, managed by NEXCO Central Nippon, have aged significantly among expressways nationwide. We have been working on an Expressway Renewal Project that includes replacing bridge decks in order to keep expressways, which are an important transport infrastructure, in a sustainably good condition, while also to maintain a much safer and more comfortable expressway space.

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Review
  • Sumio SHIMOKAWA
    2020 Volume 44 Issue 3 Pages 188-196
    Published: February 29, 2020
    Released: February 29, 2020
    JOURNALS FREE ACCESS

    As one approach for road improvement in Japan, there is a need to reorganize the road system into an arterial highway network suited to the use stage, by shifting the viewpoint from quantitative improvement as a “cross section allowing passage of traffic” to “mobility between transport hubs”. Various roads in different categories, such as roadside accessibility and mobility, are used efficiently in movement between travel hubs, and once the target travel time between hubs is determined, the arterial highway network is also positioned within the combination of different categories of roads that enable it. In this paper, we explain these elements and discuss some requirements that are essential to realize the speed service that the arterial highway should provide.

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Review
  • Miho IRYO
    2020 Volume 44 Issue 3 Pages 197-204
    Published: February 29, 2020
    Released: February 29, 2020
    JOURNALS FREE ACCESS

    Although pedestrian traffic safety remains a major issue, increasing deterioration and maintenance costs of traffic lights to protect safety are also becoming a problem. Recently, geometry improvements of unsignalized crosswalks - particularly the midblock two-stage type - have garnered attention as an effective alternative tool for providing safe crossing opportunities without relying on traffic signals. Some case studies in Japan have shown excellent results in terms of drivers' higher yielding rate and speed reduction. This article summarizes safety and efficiency improvement effects of unsignalized crosswalk facilities with improved geometry, as well as approaches for setting up such facilities in accordance with the road hierarchy. This is done by examining examples in Japan and abroad.

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Report
  • Hiroshi TANIGUCHI
    2020 Volume 44 Issue 3 Pages 205-213
    Published: February 29, 2020
    Released: February 29, 2020
    JOURNALS FREE ACCESS

    The city of Toyama took over the Toyamako Line, a deteriorated local railway, from the West Japan Railway Company, and over about three years, restored it as Japan's first full-fledged LRT. The opening of this LRT had a major impact on persons involved in this field throughout Japan. The project is distinctive in adopting a public-build/private-operation approach in which operations are handled by a voluntary sector organization, the Toyama Light Rail Co., Ltd., and construction and maintenance of facilities are handled by the city of Toyama. Efforts were made in this way to achieve stability as a business. Operation during the day was scheduled at 15-minute intervals (an increase of about 3.5 times over the JR era), and accessibility was markedly improved through steps like adding new stations. As a result, the number of users increased by about 2.2 times on weekdays, and 4.7 times on holidays, putting the budget into the black.

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Review
  • Kenzo TAKEUCHI
    2020 Volume 44 Issue 3 Pages 214-222
    Published: February 29, 2020
    Released: February 29, 2020
    JOURNALS FREE ACCESS

    This paper organizes the issues on what type of policy response should be taken concerning large scale renewal of high-speed railways, which is expected to occur frequently in the near future. The need for a new policy framework with a view to large scale renewal is claimed from the perspective of whether the current project assessment method assumes large scale renewal, whether, in particular, a parallel conventional train line among alternate transportation and alternate railway lines can function as a receptacle to take on the demand during the renewal, and what the cost burden and administrative support should be during the renewal.

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