• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.157-168
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• 2006

Spatial detection system such as AVI, GPS, and Beacon etc. can provide spatial travel time only after a vehicle Passes through a road section. In this context, majority of the existing studies on the link travel time estimation area has focused on the arrival time-based link travel time estimation. rather than departure time-based link travel time estimation. Even if some of the researches on this area have developed departure time-based link travel time estimation algorithms, they are limited in that they are not applicable in a real-time mode. The objective of this study is to develop an departure time-based link travel time estimation algorithm which is applicable in a real-tine mode. Firstly, this study discussed the tradeoff between accuracy and timeliness of the departure time-based on-line link travel time estimates. Secondly, this study developed an departure time-based on-line link travel time estimation algorithm which utilizes the Baysian inference logic. It was found that the proposed approach could estimate departure time-based link travel times in a real-time context with an acceptable accuracy and timeliness.

• Journal of the Economic Geographical Society of Korea
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• v.11 no.2
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• pp.192-202
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• 2008

Typical activity-based travel analysis has been focused on passenger travel using household survey data. The current research focuses on freight transport using one-day travel survey data. Passenger travel can be seen as the outcome of traveller's subjective decision-making, whereas freight transport is the outcome of shipper or transport company's optimized scheduling. The research conducts an activity-based analysis of freight-vehicle trip chains. In particular, the research focuses on the difference in travel pattern between shipper-oriented private vehicle and transport company-oriented business vehicle. The research analyzed the travel diary of freight vehicles collected as part of the third national logistic survey in 2005. The diary is freight driver's one-day travel record including the information of loading capacity, item transported, destination, arrival time, etc. The analysis results show the difference between private and business vehicles in the travel pattern regarding the sequences of destination, destination type and item transported and the multi-dimensional information of the three sequences.

• Journal of Korean Society of Transportation
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• v.21 no.3
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• pp.7-14
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• 2003

Statistics shows that 80% of freeway users travel less than 50km, and only 8% of them do over 100km. It means that the freeway is used for commuting. As a result, the freeway is not used efficiently and social cost is high. The current toll system aims for the efficient usage of the freeway by restraining short-distance trips and inducing long-distance ones. Thus, policies such as minimum toll system and discount for long-distance trips have been carried out. However. these two policies take no account of demand management between the freeway and alternative roads. They merely consider the compensation for charge on users, so the assessment of discount rate and distinction of distance are not reasonable. Consequently, not only the effective demand management but also the evaluation of those policies has been difficult to be achieved. The objective of this paper is to analyze those problematic policies and to establish a reasonable and improved toll system. In addition, this study presents the methodology to minimize social cost, which can be achieved by reducing short trips and encouraging long ones on the freeway. A new methodology of freeway toll system is applied and the results are presented.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.109-120
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• 2004

Since the late of 1990, there have been number of studies on the required number of probe vehicles and/or optimal aggregation interval sizes for travel time estimation and forecasting. However, in general one to five minutes are used as aggregation intervals for the travel time estimation intervals for the travel time estimation and/or forecasting of loop detector system without a reasonable validation. The objective of this study is to deveop models for identifying optimal aggregation interval sizes of loop detector data for travel time estimation and prediction. This study developed Cross Valiated Mean Square Error (CVMSE) model for the link and route travel time forecasting, The developed models were applied to the loop detector data of Kyeongbu expressway. It was found that the optimal aggregation sizes for the travel time estimation and forecasting are three to five minutes and ten to twenty minutes, respectively.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.6
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• pp.40-48
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• 2012

In this paper, we suggests methods for determining optimal representative value and the optimal size of historical data for reliable travel speed prediction. To evaluate the performance of the proposed method in real world environments, we did field tests at four roadway links in Seoul on Tuesday and Sunday. According to the results of applying the methods to historical data of Central Traffic Information Center, the optimal representative value were analyzed to be average and weighted average. Second, it was analyzed that 2 months data is the optimal size of historical data used for travel speed prediction.

• Journal of Korean Society of Transportation
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• v.29 no.3
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• pp.83-91
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• 2011

This paper discusses models for estimating dynamic travel times based on probability theory. The dynamic travel time models proposed in the paper are formulated assuming that the travel time of a vehicle depends on the distribution of the traffic stream condition with respect to the location along a road when the subject vehicle enters the starting point of a travel distance or with respect to the time at the starting point of a travel distance. The models also assume that the dynamic traffic flow can be represented as an exponential distribution function among other types of probability density functions.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.12
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• pp.1373-1380
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• 2014

In order to calculate accurate traffic and traffic speed, qualified and sufficient GPS data should be provided. However, it is difficult to provide accurate traffic information using restricted GPS data from probe vehicles because of communication costs. This paper developed a algorithm that recovers links omitted by restricted GPS data with topology information, and calculate traffic speed with original links and recovered links. T traffic information service of city with a new algorithm can provide more accurate traffic and traffic speed than the original system.

• Journal of Korean Society of Transportation
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• v.12 no.4
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• pp.65-88
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• 1994

교통수요와 공급은 상호 밀접한 연관성을 지니고 있다. 교통수요는 교통시설 서비 스수준 및 교통시설의 이용가격에 영향을 미치는 반면에 교통시설 공급비용과 서비스수준은 교통수요에 영향을 준다. 또한, 교통수요와 공급간의 상호작용은 도시공간상에서 발생하기 때문에 교통시스템의 공간적 구조 및 도시의 공간적 특성은 공급, 가격 및 수요를 통합한 교통균형모형에 있어서 매우 중요한 영향인자로 작용하게 된다. 그러나, 이제까지 개발된 교통균형모형에서는 통행인의 통행시간가치 및 교통체증의 도시공간상 변화가능성을 적절하 게 반영하지 못하고 있다. 본 연구에서는 도시공간상에서 통행인의 통행시간가치 변화패턴 을 반영한 수 도시공간상에서의 교통시설의 최적 서비스 수준, 교통수단별 최적요금체계를 도출할 수 있었다. 단핵도시구조를 지닌 도시공간상에서의 최적버스요금은 통행거리에 따라 할증되는 체계를 가져야 한다. 선행연구에서는 승용차에 대한 통행혼잡세 부과는 소득역분 배적인 효과를 초래하는 것으로 알려졌다. 그러나 버스의 요금구조나 서비스 수준이 최적수 준에서 제공된다면 통행혼잡세는 소득역분배적 결과를 초래하지 않는 것으로 나타났다.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2023.11a
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• pp.255-256
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• 2023

본 연구에서는 코로나19로 인하여 전국적으로 전례 없는 통행체계 위축 등 통행행태 변화가 발생되어 수도권 및 인천시 지역적 세부 통행체계에 대하여 네트워크 중심성 분석을 통하여 지역별 교통 거점과 외부 영향에 따른 지역적 교통 거점 변화를 비교 분석하였다. 또한, 대중교통 이용통행 분석 결과, 코로나19 유행 시기별로 통행량이 크게 감소됨에 따라 버스, 지하철 등 수단별 대책 마련하는데 기여할 것으로 판단된다.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.33-43
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• 2002

Travel choice behavior is affected by real-time traffic information. Recently, in urban area, real-time traffic information is provided by several instruments such as transportation broadcasting, internet PC network and variable message sign, etc. Furthermore, it has been increasing for urban travelers to use real-time traffic information provided by several instruments. The purpose of this study is to analyze the effects of advanced traveler information on urban worker's travel choice behavior. Among several Advanced Traveler Information System(ATIS) employed in urban area. This study focuses on examining the effects of transportation broadcasting on urban worker's travel choice behavior. This study attempts to examine traveler's mode change behavior in the pre-trip stage and traveler's route change behavior in the on-route stage. For this study, the survey data collected from Daegu City in 2000 is used. For empirical analysis, several nested logit models are estimated, and among them, the best models are reported in this paper. Furthermore, based on the empirical models estimated for this research, important findings and their policy implications are discussed.