• Transportation Technology and Policy
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• v.10 no.2
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• pp.75-80
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• 2013

• Proceedings of the KOR-KST Conference
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• 2007.05a
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• pp.352-361
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• 2007

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.107-118
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• 2022

As connected and automated driving(CAD) technology is entering its commercialization stage, service platforms providing CAD-based mobility services have increased these days. However, CAD-baded mobility services with these platforms need more consideration for the demand for mobility services when determining target areas for CAD-based mobility services because current CAB-based mobility design focus on driving performance and driving stability. For a more efficient design of CAD-based mobility services, we analyzed the applicability for the introduction of CAD-based mobility services in terms of driving difficulty of CAD and demand patterns of current non-CAD based-mobility services, e.g., taxi, demand-responsive transit(DRT), and special transportation systems(STS). In addition, for the spatial analysis of the applicability of the CAD-based mobility service, we propose the Index for Autonomous Driving Applicability (IADA) and analyze the characteristics of the spatial distribution of IADA from the network perspective. The analysis results show that the applicability of CAD-based mobility services depends more on the demand patterns than the driving difficulty of CAV. In particular, the results show that the concentration pattern of demand in a specific road link is more important than the size of demand. As a result, STS service shows higher applicability compared to other mobility services, even though the size of demand for this mobility service is relatively small.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.19-26
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• 2004

AllWayS(AWS, Satongpaldal in Korean) is the first comprehensive computer software in Korea that is developed for the transportation demand modeling. The original DOS version software was recently receded for Windows environment. Traditional 4-step transportation demand forecasting process is incorporated in the software under graphical user interface environment. AWS is able to compose or edit graphic transportation networks data by each scenario which could be the subject of an analysis. Besides, it use database structure that can handle every data of a scenario such as networks, O/D, and socio-economic data, etc. We expect this integrated process could provide each analyst with efficient and easy to use tool for their analysis. Each models in this software is based on traditional algorithms and the results were compared to existing software, EMME/2 and it showed similar results.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2020.11a
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• pp.175-176
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• 2020

시뮬레이션 기반의 해상교통 분석 방법은 대상 항만의 항적 데이터를 이용하여 교통 특성 모델을 구축하고, 이를 통해 해상교통 현상을 재현함으로써 분석을 수행하는 방법이다. 교통 특성 모델은 교통 현상을 수치적으로 표현한 일반화 된 모형을 말하며, 모델링 작업에 많은 시간과 노력이 소요된다. 본 논문에서는 해상 교통 특성을 생성하기 위한 자동화 된 프로세스를 제안하며, 실제 목포항의 항적 데이터에 적용하여 교통특성 정보 생성 방법으로서의 활용 가능성을 검토하였다.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.183-191
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• 2002

본 논문은 ATIS의 효과를 평가할 수 있도록 교통정보제공에 따른 운전자의 노선선택 행태자료를 수집할 수 있는 시뮬레이터 개발에 관한 것이다. 현재 이러한 행태자료를 수집하기 위해서 설문지에 의한 SP(Stated Preference) 설문조사가 널리 수행되어지고 있으나 이러한 설문조사방법은 ATIS와 같은 가상의 환경을 응답자에게 이해시킬 수 있는 설문지를 작성하기가 힘들고, 무엇보다 운전중에 느끼게 되는 time pressure를 현실적으로 반영하지 못하기 때문에 신뢰성있는 자료를 수집하는데 어려움이 있다. 시뮬레이터는 보다 현실적인 교통상황을 계산하고 적절한 인터페이스 구성을 통해 교통상황과 분석자의 설문 의도를 응답자에게 효과적으로 인지시킬 수 있다는 장점을 가지고 있다. 본 연구에서 세 가지 모듈(교통 시뮬레이션 모듈, 데이터베이스 모듈, 이용자 인터페이스 모듈)로 구성된 프로토타입 시뮬레이터를 개발하였다. 개발된 프로토타입의 유용성을 알아보기 위해 실제로 실시간 교통정보가 제공되는 작은 네트워크를 대상으로 파일럿 테스트를 수행하였고, 수집된 자료는 discrete choice model을 정산하는데 사용하였으며 그 분석결과는 상당히 합리적인 것으로 나타났다. 따라서, 이러한 시뮬레이터는 교통정보전략에 따른 효과를 사전에 분석해보고, 효과적인 교통정보시스템을 설계 및 운영하는데 활용될 수 있을 것이다.

• Journal of Korean Society of Transportation
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• v.21 no.6
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• pp.77-88
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• 2003

This paper proposes a solution algorithm for solving a multi-class analytical DTA model. In the DTA model, three traveler classes are classified according to different assumptions of traveler's route choice behavior: including fixed route, Stochastic Dynamic User Optimum(SDUO), and Dynamic User Optimum(DUO). To solve this DTA model, variables of link flow and exit flow are represented solely by inflow. The resulting Linear Program(LP) subproblem in the inner iteration is solved as a typical time-dependent shortest route problem over a physical network. Accordingly, the required time-space network expansion in solving DTA models is no longer needed.

• Journal of Korean Society of Transportation
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• v.28 no.1
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• pp.115-124
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• 2010

VDF(volume-delay function) is one of the most important factor to improve the reliability of traffic demand estimation because it is for estimation of link travel time based on the traffic volume variation. Because VDF of link except for freeway is applied as the parameter of BPR(bureau of public road) of U.S., it causes to deteriorate the accuracy of traffic demand estimation. The purpose of this paper is to establish new parameter of VDF based on the real-surveyed traffic data in order to improve the problem of the existing VDF. We suggest the reclassification of road hierarchy, the approach of traffic survey, the estimating method of VDF parameter, and the improvements of new VDF application. The new VDF allows us to estimate more realistic traffic situation in parts of demand, travel time and path between origin-destination.

• Journal of Korean Society of Transportation
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• v.19 no.5
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• pp.49-59
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• 2001

In the transportation planning process, origin and destination(O-D) trip matrix is one of the most important elements. There have been developments and applications of the methodology to adjust old matrices using link traffic counts. Commonly, the accuracy of an adjusted O-D matrix depends very much on the reliability of the input data such as the numbers and locations of traffic counting points in the road network. In the real application of the methodology, decisions on the numbers and locations of traffic counting points are one of the difficult problems, because usually as networks become bigger, the numbers of traffic counting points are required more. Therefore, this paper investigates these issues as an experiment using a nationwide network in Korea. We have compared and contrasted the set of link flows assigned by the old and the adjusted O-D matrices with the set of observed link flows. It has been analyzed by increasing the number of the traffic counting points on the experimental road network. As a result of these analyses, we can see an optimal set of the number of counting links through statistical analysis, which are approximately ten percentages of the total link numbers. In addition, the results show that the discrepancies between the old and the adjusted matrices in terms of the trip length frequency distributions and the assigned and the counted link flows are minimized using the optimal set of the counted links.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.1-20
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• 2022

The basic way to charge vehicles for using road and public transport networks is the entry-exit toll system. This system works by reading Hi-Pass and public transportation cards of the vehicles using card readers. However, the problems of navigating a route in consideration of entry-exit toll systems include the non-additive costs of enumerating routes. This problem is known as an NP-complete task that enumerates all paths and derives the optimal path. So far, the solution to the entry-exit toll system charging has been proposed in the form of transforming the road network. However, unlike in the public transport network where the cards are generalized, this solution has not been found in situations where network expansion is required with a transfer, multi-modes and multiple card readers. Hence, this study introduced the Link Label for a public transportation network composed of card readers in which network expansion is bypassed in selecting the optimal path by enumerating the paths through a one-to-one k-path search. Since the method proposed in this study constructs a relatively small set of paths, finding the optimal path is not burdensome in terms of computing power. In addition, the ease of comparison of sensitivity between paths indicates the possibility of using this method as a generalized means of deriving an optimal path.