• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.2
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• pp.73-86
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• 2018

The increase in the number of private automobiles has incurred various traffic problems. Globally, studies on MaaS(Mobility as a Service) has already been initiated to mobilize the use of public transportation in reducing private passenger cars in roads. This study aims to analyze the passenger's optimal route considering the transfer between different transportation modes through simulation, and analyze the effect of available route through the connected transportation modes. Sejong Special Self-Governing City was chosen as the study area due to its extensive transportation network. As a result of the analysis, the predominant obtainable route is derived either from using public transportation (i.e. bus and subway) only or by bicycle. However, it is also possible to use the car sharing and public bicycle to reach their final destination efficiently when paths that can be traversed were more scrutinized. When various transportation information and location-based services are introduced in smart phone applications, they can provide very useful information to passengers, and also promote social problems such as traffic congestion and environmental issues in the future.

• Journal of Korean Society of Transportation
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• v.30 no.2
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• pp.29-42
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• 2012

Recently, traffic congestion has become serious due to increase of private car usages. Carsharing or other innovative public transportation systems were developed to alleviate traffic congestion and carbon emissions. These measures can make the traffic environment more comfortable, and efficient. Cloud Transportation System (CTS) is a recent carsharing model. User can rent an electronic vehicles with various traffic information through the CTS. In this study, a concept, vision and scenarios of CTS are introduced. And, authors analyzed the location of CTS rental stations and estimated CTS demands. Firstly, we analyze the number of the population, employees, students and traffic volume in study areas. Secondly, the frequency and utilization time are examined. Demand for CTS in each traffic zone was estimated. Lastly, the CTS rental station location is determined based on the analyzed data of the study areas. Evaluation standard of the determined location includes accessibility and density of population. And, the number of vehicles and that of parking zone at the rental station are estimated. The result suggests that Haewoondae Square parking lot would be assigned 11 vehicles and 14.23 parking spaces and that Dongbac parking lot be assigned 7.9 vehicles and 10.29 parking spaces. Further study requires additional real-time data for CTS to increase accuracy of the demand estimation. And network design would be developed for redistribution of vehicles.

• IE interfaces
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• v.23 no.4
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• pp.286-299
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• 2010

Recently, as concerns about environmental improvement have increased, various environmentally friendly transportation services have been developed and introduced. However, the effect on the introduction of such services has been not analyzed through a systematic methodology and process. Therefore, this research aims at suggesting a framework to analyze the effect of an environmentally friendly transportation service and investigating the validity of the framework. To the ends, a process to analyze the degree of improvement in transportation systems and environments, the linkage with existing policies, and profitability of the service is proposed. In addition, the concept and value of carsharing service, a representative environmentally friendly transportation service are explained and then the effects of the service are examined in terms of the aforementioned analytic areas, respectively. The results of this research can be utilized to provide the validity of a newly developed environmentally friendly transportation service and reflected to the policies of transportation and environment.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.2
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• pp.28-36
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• 2016

Recently, owing to the development of ICT industry and wide spread of smart phone, the number of people who use car sharing service are increased rapidly. Currently two-way car sharing system with same rental and return locations are mainly operated since this system can be easily implemented and maintained. Currently the demand of one-way car sharing service has increase explosively. But this system have several obstacle in operation, especially, vehicle stock imbalance issues which invoke vehicle relocation. Hence in this study, we present an optimization approach to depot location and relocation policy in one-way car sharing systems. At first, we modelled as mixed-integer programming models whose objective is to maximize the profits of a car sharing organization considering all the revenues and costs involved and several constraints of relocation policy. And to solve this problem efficiently, we proposed a new method based on particle swarm optimization, which is one of powerful meta-heuristic method. The practical usefulness of the approach is illustrated with a case study involving satellite cities in Seoul Metrolitan Area including several candidate area where this kind systems have not been installed yet and already operating area. Our proposed approach produced plausible solutions with rapid computational time and a little deviation from optimal solution obtained by CPLEX Optimizer. Also we can find that particle swarm optimization method can be used as efficient method with various constraints. Hence based on this results, we can grasp a clear insight into the impact of depot location and relocation policy schemes on the profitability of such systems.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.3
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• pp.61-69
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• 2019

The concept of carsharing involves sharing a small number of reserved cars to be used individually by a larger number of people as required. This study examines the operating parameters of one-way carsharing systems in order to determine the appropriate operating conditions that minimizes the lost sales rate. Five operating parameters are tested in this study: the number of stations, the average number of vehicles per station, the rate of one-way trip, the average number of staffs per station, and the relocation policy. The performance of round-trip carsharing systems is also compared to that of one-way carsharing systems. A simulation model is developed and simulations are performed to determine the appropriate combination of operating parameter and levels. The simulation results show that the average number of vehicles per station is the most critical parameter. Other key findings obtained from this research are as follows. First, applying the appropriate relocation policy to one-way carsharing systems can allow more customers to rent vehicles than the traditional round-trip carsharing systems. Second, the appropriate relocation policy should be selected based on the average number of vehicles per station in order to minimize the lost sales rate. Third, the number of stations does not affect the lost sales rate. This study findings will provide tools to understand impact of the carsharing system parameters on the efficiency of the carsharing operations.