• Journal of Korean Society of Transportation
• /
• v.27 no.6
• /
• pp.147-156
• /
• 2009

We present a methodology for modeling and solving the transit frequency design problem with variable demand. The problem is described as a bi-level model based on a non-cooperative Stackelberg game. The upper-level operator problem is formulated as a non-linear optimization model to minimize net cost, which includes operating cost, travel cost and revenue, with fleet size and frequency constraints. The lower-level user problem is formulated as a capacity-constrained stochastic user equilibrium assignment model with variable demand, considering transfer delay between transit lines. An efficient algorithm is also presented for solving the proposed model. The upper-level model is solved by a gradient projection method, and the lower-level model is solved by an existing iterative balancing method. An application of the proposed model and algorithm is presented using a small test network. The results of this application show that the proposed algorithm converges well to an optimal point. The methodology of this study is expected to contribute to form a theoretical basis for diagnosing the problems of current transit systems and for improving its operational efficiency to increase the demand as well as the level of service.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.1D
• /
• pp.133-139
• /
• 2011

We built subway stops in order to meet demand. To do so, a standardized method is used to predict the demand. However, in some subway stops there are only few people moving around sparsely, but in some other stops there are too many people crammed in a crowd. The gap between forecasting and actual uses varies from 10% to more than 1,000%. This study is aimed to find out where this discrepancy between predicted vs. actual demand for urban rail transit comes from. Specifically, 40 subway stops in Seoul Metropolitan Area, which were opened last 10 years, are examined. This study suggests that, for better forecasting, we need to consider stops' locational characteristics as well as weekday commute-oriented exogenous factors. Locational characteristics includes; whether a stops is a terminal and/or weekend tourism node. There seems no "one size fits all" solution for transit demand forecasting; locational characteristics need to be reflected.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.6
• /
• pp.2604-2611
• /
• 2013

The Personal Rapid Transit(PRT) system has been highly interested in future transportation developments due to its on-demand and optimized door-to-door transport capability. However, the major impediments to the commercialization of PRT are the high cost for construction of infrastructures as opposed to the small transport capacity and difficulty in defining the role of PRT in building a balanced transportation system. In this study, the vertical transfer device for the PRT vehicle is developed to provide more flexible and better compatible urban mobility services between means of transportation, which is expected to meet particular demands in a particular environment. This apparatus was initially designed based on the basis of vertical circulating conveyors with steel chains, which is frequently used in logistics. Its advantages are capable of the non-stop loading and reduced head-way time. Most importantly, it was intensified by the additional idea to ensure the stable and reliable transfer of the PRT vehicle fully loaded with passengers. The 1/10-scale prototype was successfully tested to demonstrate a fundamental mechanism of vertical transfer and identify unexpected user requirements prior to a real manufacturing process.

• Journal of the Korean Society for Railway
• /
• v.11 no.6
• /
• pp.550-561
• /
• 2008

The purpose of this paper is to propose a new transit assignment model for intercity rail networks. The characteristics of intercity rail are different from that of public transit in urban area. Line selection probability on route section is introduced to include the characteristics of intercity rail into transit assignment model. Network expansion is more simplified by a assumption line selection probability is externally given. The generalized cost is used to decide the volume of each transit line in most of existing transit assignment models. But, many variables have influence on the volume of each line such as time schedule of transit lines, inter-station distance, passengers' income, seasonal variation of demand and regional characteristics. The influence of these variables can be considered to decide the volume of each line by introducing line selection probability on route section. The tests on a small scale network show that the model proposed in this paper is superior to existing models for predicting intercity rail demand. Proposed model is suitable to consider the complicated fare structure of intercity rail and to draw inter-station demand directly as a result of assignment procedure.

• Proceedings of the KSR Conference
• /
• 2005.11a
• /
• pp.197-202
• /
• 2005

On December 2001, Yongin Light Rapid Transit was started with the Notification of Basic Plan for Private Infrastructure Investment Project and promoted as BTO configuration to effectually cope with the rapid increase of traffic demand in Yongin City and establish pleasant and green urban traffic system to connect with New Boondang Line to diversity traffic demand around roads. On May 27th, 2005, it was applied authorization of detailed plan and the .First Light Rapid Transit in Korea shall be started construction on Nov, 2005, and completion on May. 2009. This Thesis will introduce the Detailed Design for Yongin Light Rapid Transit.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.38 no.3
• /
• pp.23-35
• /
• 2013

It is very important that the calculation of railroad track capacity in infrastructure investment analysis and train operation planning. The dwelling time is one of the factors that influence in railroad track capacity. Current research in dwelling time has been focusing on theoretical investigation, the state of the research in effective variable (dwelling time etc) is insufficient. In this paper, we clearly draw the concept of railroad track capacity and the estimate on modeling of relationship railway demand and dwelling time. Also, we compare and analyze the variation of railroad track capacity according to transit railway demand in Gyeongin Line (Guro~Inchon). This paper is expected to contribute for improving on the in-using equations and methods in train operation planning as well as for improving level of service on railway user.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.19 no.5
• /
• pp.82-96
• /
• 2020

The Demand Responsive Transit (DRT) system is the flexible public transport service that determines the route and schedule of the service vehicles according to users' requests. With increasing importance of public transport systems in urban areas, the development of stable and fast routing algorithms for DRT has become the goal of many researches over the past decades. In this study, a new heuristic method is proposed to generate fast and efficient routes for multiple vehicles using demand clustering and destination demand priority searching method considering the imbalance of users' origin and destination demands. The proposed algorithm is tested in various demand distribution scenarios including random, concentration and directed cases. The result shows that the proposed method reduce the drop of service ratio due to an increase in demand density and save computation time compared to other algorithms. In addition, compared to other clustering-based algorithms, the walking cost of the passengers is significantly reduced, but the detour time and in-vehicle travel time of the passenger is increased due to the detour burden.

• Journal of Korean Port Research
• /
• v.8 no.1
• /
• pp.3-15
• /
• 1994

Most of Cities are suffering from the traffic congestion problem with the vehicles increased. Especially, the City of Pusan is experiencing the severest traffic congestion with the lower read capacity and the higher travel demand than any other cities in the country. Thus, the purpose of this study was to grasp the conditions, review the problems and finally suggest the improvements which we faced at this time for the construction of the Urban Transportation System considered in Pusan area. Based upon the results, it was concluded that firstly the Urban Transportation System(UTS) in Pusan area should be constructed by the Public Transportation System in the center of the Public Transit Modes(i.e., bus and subway), secondly the Para-transit Modes(i.e., Light Rail Transit, LRT) introduced, and thirdly the Transportation Demand Management(TDM) implemented with the expansion of the transportation facilities if possible.

• Journal of the Korean Society for Railway
• /
• v.16 no.2
• /
• pp.129-137
• /
• 2013

This study This study aims to identify sound developmental directions for transit-oriented development (TOD), which is a topic of interest in the field of urban development, and conducts an empirical analysis of station influence areas within Seoul according to the characteristics of transit types. The results suggest that there are differences among variables that influence demand for public transportation according to transit types. This means that it is necessary to identify improvement plans in developing public transport strategies for the capital region based on such differentiated influence factors and to build foundations to continue to increase demand for public transportation. Also, station influence areas should be developed into hubs by establishing appropriate bus-only lane networks as a supplementary means, rather than directly connecting subway stations with each other.

• Journal of Korean Society of Rural Planning
• /
• v.14 no.3
• /
• pp.27-36
• /
• 2008

Rapid increase of aging population and progressed migration from rural areas to urban areas have caused deficit of bus routes in local cities. This increasing burden of operation deficit affects the movement strategy of the transportation vulnerable who are using buses. Along with dramatically increased aging in Korea, there is an urgent need to implement a new method which can guarantee mobility rights of public transportation especially for the elderly. This study focuses on the case of Demand Responsive Transit(DRT) system that has been operating in America, Europe, Japan, etc. Kimhae(Sangdong-myeon and Saengnim-myeon) is selected as a study area. This study investigated the possibility of adopting DRT system on the perspectives of the consumer and provider by the analysis of traffic condition such as the number of transportation vehicles, present bus service and regulation and conduct of questionnaire survey which includes present bus service and DRT system and so on. In conclusion, DRT system in Kimhae city will reduce transport cost, increase affordability through the betterment of service level and secure mobility rights for the transportation vulnerable.