• Journal of Korean Society of Transportation
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• v.27 no.6
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• pp.45-53
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• 2009

This study presumes the efficiency of each route by utilizing data of Seoul's exclusive bus routes for the 2008 and the DEA model. In the estimation, it is assumed that the number of passengers and profits of each route is calculated by considering the number of buses and stops, travel distance, intervals and management cost. This study computed the efficiency scores of each bus line in Seoul based on the data for the first half of 2008 and one of the DEA models, namely the BCC model. After analysis using the input-oriented BCC model, out of a total of 18 lines of interest, there were 2 CRS lines and 16 IRS lines. Also, the Tobit Regression Analysis that helps identify the impact of the elements used in the analysis on efficiency scores proved that the most influential element to exclusive buses is the length of intervals.

• Journal of Korean Society of Transportation
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• v.28 no.5
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• pp.43-54
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• 2010

In order to improve the existing evaluation system of bus services and gain more reasonable analysis outputs, the authors evaluate the efficiency of 113 arterial bus routes in Seoul in 2009 using a modified BCC model considering not only desirable outputs but also undesirable outputs. Each Decision Making Unit (DMU) is assumed to use inputs such as possession costs, operating costs, the ratios of median bus stops overlapped route lengths to produce estimates of desirable outputs (the number of passengers and service satisfaction score) and undesirable outputs (CO2 emissions). According to the analysis, the modified BCC model considering both desirable outputs and undesirable outputs shows more appropriate results. DMUs would be more efficient on average to reduce nearly 10% of the 3 inputs (possession costs, operating costs, and overlapped route lengths) and increase by about 160% the ratios of median bus stops. Also, a Tobit regression analysis is conducted to identify the most effective variables for maximum efficiency and discover that the variable of possession costs and the ratios of median bus stops are statistically significant.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.2041-2048
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• 2013

It is necessary to evaluate methods for reasonable diagnosis for public transportation. However, previous studies have the problems in evaluation ground and propriety. Therefore, this research develop the method and equation for evaluating bus route considering interregional equity and route doubleness. This study developed in bus route evaluation method using Seoul bus Zone, and included the result of evaluation test using 199 route Seoul trunk bus (blue bus). Zone (0) (Jongno-gu, Jung-gu and Yongsan-gu) has the highest score in Evaluation result. Also this zone has good bus route, so it is easy to move to other Zone. It is possible to change and add the bus route to use the equation in this study, considering interregional equity.

• Journal of Korean Society of Transportation
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• v.27 no.1
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• pp.63-71
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• 2009

The purpose of this paper is to identify unreliable routes in the view of users. After headway error ratio per route and travel time error ratio per route were calculated by using BMS data, reliability which incorporated two indicators each route was calculated through data envelopment analysis. Reliability among routes and among traffic zones was compared through the results, the needs to improve severely unreliable routes and to show passengers adjusted bus schedule information considering current reliability were suggested. As a future study, reliability evaluation framework of each route needs to be developed considering operation environment by analyzing bus card data (passengers and operation speed etc.) and pooly unreliable route should be managed strictly and reformed.

• Journal of Korean Society of Transportation
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• v.31 no.4
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• pp.18-31
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• 2013

The operational purpose of exclusive bus lanes is to ease traffic congestion through the increase of person-carrying capacity on arterial roads. It is necessary to study on the route suitability for exclusive bus lanes because their operation may worsen traffic congestion due to the misuse of general purpose lane for an exclusive bus lane. This research quantifies the route suitability for exclusive bus lanes in Kwangju-city utilizing 7 indexes such as bus traffic volume, number of bus routes, traffic volume per lane, number of lane, number of intersection, number of streets, rate of curvature for the exclusive bus lane, recognizing the problem that the current installation standard of exclusive bus lanes is only limited to the bus traffic volume and the number of bus passengers. In addition, this research analyzes the operational efficiency for exclusive bus lanes, which is currently operated and their optimal operation hours.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.223-229
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• 2010

The bus transfer system has been extended from Seoul to Gyonggi province to provide better Seoul metropolitan area transit service in September, 2008. Moreover, the curved bus routes, except existing rapid bus routes, which cause longer travel time have been straightened out. Also, the Skip Stop operation suggested by passengers has been introduced to main stops in the newly added express bus lines. This study surveyed passengers service satisfaction for the recent adopted bus policies such as the transfer discount system and the express bus system in Seoul Metropolitan area. The survey results may be important foundation for future strategies for improvement. The survey included questionnaires about the importance and the satisfaction level on both quantitative and qualitative factors. The results were statistically analyzed by the modified IPA (Importance-Performance Analysis). As the result of the survey, the newly adopted services such as fare system, fare discount on transferring, travel time savings and increased number of stops are economically feasible and satisfactory, whereas the accessibility to stops, ventilation and air quality in vehicles are the priorities to be improved. Also, the safety and the information system is in need of improvement.

• Journal of Korean Society of Transportation
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• v.28 no.1
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• pp.135-142
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• 2010

The convenient techniques for predicting the bus arrival time have used the data obtained from the buses belong to the same company only. Consequently, the conventional techniques have often failed to predict the bus arrival time at the downstream bus stops due to the lack of the data during congestion time period. The primary objective of this study is to overcome the weakness of the conventional techniques. The estimation model developed based on the data obtained from Bus Information System(BIS) and Bus management System(BMS). The proposed model predicts the bus arrival time at bus stops by using the data of all buses travelling same roadway section during the same time period. In the tests, the proposed model had a good accuracy of predicting the bus arrival time at the bus stops in terms of statistical measurements (e.g., root mean square error). Overall, the empirical results were very encouraging: the model maintains a prediction job during the morning and evening peak periods and delivers excellent results for the severely congested roadways that are of the most practical interest.

• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.49-58
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• 2009

Four alternative plans for the bus network in Daejeon metropolitan city, which have different hierarchical structure, were proposed : Alternative 1 represents a bus network without hierarchical structure, and Alternative 2, 3, and 4 represent bus networks with primary, intermediate, and advanced hierarchical structures, respectively. Efficiency of the alternative plans were evaluated based on the evaluation index including travel time cost, waiting time cost, and transition penalty cost. The travel time cost was decreased as the level of hierarchical structure gets higher until it reaches the extremely high level. As the level of hierarchical structure get higher, the waiting time cost significantly decreased while the transition penalty cost increased. Collectively, a bus network with hierarchical structure was shown to be more efficient than without it in the light of total travel cost. For the bus network with hierarchical structure, total travel cost shows a concave curve, which implies that there exists an optimal level of hierarchical structure in a bus network.

• Spatial Information Research
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• v.22 no.5
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• pp.65-75
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• 2014

Bus headway plays an important role not only in determining the passenger waiting time and bus service quality, but also in influencing the bus operation cost and passenger demand. Previous research on headway control has considered only an hourly difference in the distribution of ridership between peak and non-peak hours. However, this approach is too simple to help manage ridership demand fluctuations in a short time scale; thus passengers' waiting cost will be generated when ridership demand exceeds the supply of bus services. Moreover, bus ridership demand varies by station location and traffic situation. To address this concern, we propose a headway control algorithm for minimizing the waiting time cost by using Smart Card data. We also provide proof of the convergence of the algorithm to the desired headway allocation using a set of preconditions of political waiting time guarantees and available fleet constraints. For model verification, the data from the No. 143 bus line in Seoul were used. The results show that the total savings in cost totaled approximately 600,000 won per day when we apply the time-value cost of waiting time. Thus, we can expect that cost savings will be more pronounced when the algorithm is applied to larger systems.

• Journal of Korean Society of Transportation
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• v.24 no.1 s.87
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• pp.109-120
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• 2006

Since the 1st of July, 2004, the public transport system of the Seoul metropolitan area has been rearranged. In the new system, bus lines are divided into 4 classes-wide area, arterial road, branch, and rotation lines with renewed fare system based on the total distance travelled. Since central control center known as the Bus Management System (BMS) integrates the entire system operation. it now becomes feasible to collect travel information and provide it to the users scientifically and systematically. The Purpose of this study is to forecast transit travel time using real-time traffic data coming from both buses and subway. This is significant contribution since provision of real-time transit information and easy access to it would most likely boost the use of mass transit system, alleviating roadway congestion in the metropolitan area.