• Journal of Korean Society of Transportation
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• v.29 no.4
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• pp.53-62
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• 2011

This study discusses the effectiveness of safety management programs resulted from examining crash data collected during the period of implementation of the programs by a commercial transport company. For the analysis, two tye of comparison approaches are adopted: 1) a study comparing before-after of the implementation of a safety program, and 2) a study comparing a traffic accident index for various target groups. Technically, the effect of the safety management program is derived by eliminating both the 'regression to the mean' and the changing trend in the traffic accident index. The results show that safety management programs are effective to prevent traffic accidents, whereas company type appears irrelevant. The results also show that the effectiveness is significantly different depending on the intensity of safety management program and company size. In addition, a reciprocal effect is very likely to existamong the combination of these variables. This indicates that in order to improve the accident reduction effectiveness of such programs, the development and application of safety management programs based on both safety management strength and company size are required.

• Journal of Korean Society of Transportation
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• v.34 no.5
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• pp.421-436
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• 2016

Public-Private-Partnerships tend to be committed high project development cost and recover the cost through future revenue during the operation period. In general, long-term concession can bring on more revenue to private investors, but short-term concession less revenue due to the short recovering opportunities. The concession period is usually determined by government in advance or by the private sectors's proposal although it is a very crucial factor for the PPPs. Accurate traffic forecasting should be most important in planing and evaluating the operation period in that the forecasted traffic determines the project revenue with user fees in PPPs. In this regards, governments and the private investors are required to consider the traffic forecast risk when determining concession period. This study proposed a model for the optimal concession period in the PPPs transportation projects. Monte Carlo simulation was performed to find out the optimal concession period while traffic forecast uncertainty is considered as a project risk under the expected return of the private sector. The simulation results showed that the optimal concession periods are 17 years and 21 years at 5.5% and 7% discount level, respectively. This study result can be applied for the private investors and/or any other concerned decision makers for PPPs projects to set up a more resonable concession period.

• Journal of Korean Society of Transportation
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• v.34 no.4
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• pp.354-372
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• 2016

This study identified factors affecting the crash severity at freeway work zones. A nice feature of this study was to take into account the characteristics of work zone traffic management in analyzing traffic safety concerns. In addition to crash records, vehicle detection systems (VDS) data and work zone historical data were used for establishing a dataset to be used for statistical analyses based on an ordered probit model. A total of six safety improvement strategies for freeway work zones, including traffic merging method, guidance information provision, speed management, warning information systems, traffic safety facility, and monitoring of effectiveness for countermeasures, were also proposed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.165-176
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• 2022

In order to prevent various accidents with construction machinery, Korea enacted the Construction Machinery Management Act to enhance safety. Until now, there has been a lack of systematic research related to traffic accidents with construction machinery. Therefore, domestic and foreign systems related to construction machinery were reviewed, and the current status was analyzed based on traffic accident data over the past 5 years to derive implications. It is necessary to ensure the safety of construction machinery by correcting institutional loopholes and preparing follow-up measures. In addition, it is necessary to create a separate traffic-safety education program for construction machinery operators to create an environment that can comply with safe road-driving methods and traffic laws.

• Journal of Korea Spatial Information System Society
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• v.10 no.4
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• pp.89-95
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• 2008

In this paper, we propose an integrated techniques for managing data quality in traffic data warehousing environments. We describe how to collect and construct the traffic data warehouses from the operational databases, such as FTMS and ARTIS. We explain how to configure the traffic data warehouses efficiently. Also, we propose a quality management techniques to provide high quality traffic data for various analytical transactions. Proposed techniques can contribute in providing high quality traffic data to the traffic related users and researcher, thus reducing data preprocessing and evaluation cost.

• Journal of Korean Society of Transportation
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• v.8 no.1
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• pp.119-128
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• 1990

교통자산과 같은 내구재는 일정 기간 동안의 수명을 가지게 된다. 이 기간 동안에 내구재는 어떠한 형태로 소비되어 지고 이에 따라 내구재는 효율성을 잃어 간다. 내구재를 효율적으로 사용하기 위해서는 적절한 관리를 필요로 한다. 본 연구는 내구재를 효율적으로 사용하기 위해 필요한 관리비용의 동적형태를 이론적으로 고찰한 다음, 미국에서의 업무용 비행기의 관리비용자료를 사용하여 경험적인 결과를 제시한다. 본 연구의 결과는 다음과 같다. (1) 관리비용은 시간이 감에 따라 줄어든다. 그러나 관리비용의 잠재가격(Shadow Price)에 대한 비율은 여러 가지 외적변수들에 결정된다. (2) 미국에서의 업무용 비행기의 시장가격에 대한 관리비용의 비율은 시간이 감에 따라 늘어난다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.63-82
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• 2010

In spite of continuous road construction, traffic congestion has been worsening by radical vehicle's increase and development of surroundings near expressway. Thus, the necessity of traffic management and the needs of provision of traffic information to drivers are raised. In order to solve traffic problems, such as traffic congestion, search for optimal congestion management technique and evaluation of the effect of optimal solution should be examined prior to practice of optimal alternative. However, existing traffic analysis model and simulation programs as tools to search and evaluate optimal alternative are not sufficient to reflect traffic flow characteristics, domestic road and traffic conditions and to link up to Freeway Traffic Management Systems (FTMS). Hence, to use existing traffic analysis and simulation tools are followed by hard work to need a lot of time and cost. Therefore, in this research, Expressway TRaffic Analysis Model (ExTRAM) based on Freeway Traffic Management Systems (FTMS) was developed to apply it into congestion management easily.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.132-145
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• 2021

This study analyzes the main road network for road users to manage roads efficiently and derives problematic road sections to be improved. Traditional road management has been operated by manager-oriented view and a diversified road management system based on congestion. Therefore, in this research, the mail road Network was selected from the viewpoint of passenger-oriented, logistics-oriented and tourism-oriented, and the problematic road sections were derived through Level Of Service (LOS) analysis, safety analysis using EPDO accident rate, and network service analysis. This study emphasizes the efficient user-oriented road construction and management system and the need of constructing a mail road network, and it suggests the improvement strategies.

• Journal of Korean Society of Transportation
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• v.33 no.4
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• pp.417-429
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• 2015

Evaluation of traffic data quality is a backbone of better traffic information and management systems because it directly affects the reliability of traffic information. This study developed an integrated index for evaluating the quality of archived intelligent transportation systems (ITS) data. Two novel indices including spatio-temporal consistency and severity of missing data were devised and integrated with existing indices such as availability and completeness. An evaluation framework was proposed based on the developed integrated index. Both analytical hierarchical analysis (AHP) technique and entropy method were adopted to derive mixed weighting values to be used for the integrated index. It is expected that the proposed methodology would be effectively used in enhancing the quality of traffic data as a part of traffic information system.

• Journal of Advanced Navigation Technology
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• v.28 no.4
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• pp.436-441
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• 2024

Urban air mobility (UAM) is an innovative air traffic management system that utilizes electric vertical take off and landing aircraft(eVTOL) to transport passengers and cargo in urban areas. The corridor can be defined as the airspace that the vehicle operates in and must be collaboratively managed. For the stable operation of UAM, it is essential to have strategic separation and a collaborative decision-making(CDM) system for cooperation and coordination among stakeholders. This study examines the application of time-based milestones from traditional air traffic flow management to the UAM system to ensure safe traffic volume and optimize air traffic flow. For traffic flow management, the milestone time information is categorized into a total of 13 key milestone time indicators based on the UAM movement status, and the sharing entities providing each time indicator and the flow of milestones are defined. Emphasizing the need for a CDM to balance UAM traffic and capacity, sharing and managing milestone information among stakeholders is expected to improve UAM aircraft departure flow and enhance operational efficiency.