• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.2
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• pp.80-93
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• 2018

Public transit services are generally analyzed based on the correlation of demand and supply. The computation of supply uses accessibility while demand uses travel demands estimation based on residential population. However, the traditional demand estimation has a limitation in analysing in micro-scale compared to the smartcard data traffic. This study analyzed potential improvement of public transit services using smartcard traffic data. The supply of transportation was defined using time distance accessibility. Also, time loss was calculated in those origin destination(OD) pairs where time distance accessibilities are relatively low. The proposed method was applied at Seoul. The results showed that the areas where OD pairs need improvement include Seodaemun-gu, Guro-gu and Nowon-gu.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.3
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• pp.371-377
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• 2022

Urban rails and buses are representative public transit systems that not only cooperate with each other, but also compete with each other. In other words, there is a possibility that the overall demand for public transportation may increase due to the introduction of a competitive public transportation system, or there is a possibility that demand will be maintained at the level that is simply converted to a competitive system. The objective of this study is to analyze the change in public transit flow when an additional transit system is introduced in a city with alternative public transit systems. To carry out this objective, we analyzed changes in public transit passenger flow before and after the introduction of an urban rail transit line 3 in Daegu Metropolitan City, where two public transit systems, urban rail and bus, exist. For accurate analysis, big data collected by passenger transportation cards were utilized for one week in the second week of April 2015, 2016, and 2019. From the analysis, it was found that although the urban rail passenger flow increased due to the additional urban rail transit system, the change in the overall public transit passenger flow in the city was insignificant. In other words, it is interpreted that the bus transit passengers have been shifted to the urban transit systems. Based on the results, this study suggested various policies to increase the demand for public transit rather than simply adding public transit systems.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.113-122
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• 2008

This study extended Park et al.(2007c), which analyzed the efficiency of a hierarchical transit network, showed the result of a real data, and analyzed its applicability. Operating cost was estimated using a model which was established in this study, and minimum transit demand was derived from the operating cost. The minimum transit demand value is just a sample calculation, thus it varies by many inside and outside factors of the model. Looking at the inside of the model, operating cost and travel speed are major factors, and the possibility of introducing urban subway becomes high when the operating cost of the transit system is low and its travel speed is high. As far as the outside factors are concerned, according to the analysis on the network structure, transit demand, and transit mode share, the minimum transit demand value which was derived in this study will be the maximum value among the possible values. In the feasibility study, the benefit is likely to be overestimated and the cost is likely to be underestimated than those of this study. It could be concluded that the methodology of a feasibility study is appropriate in the field standard. This study analyzed the efficiency of introduction of urban subway using analytical approach, thus has many shortcomings and limitations. However the practical approach, like feasibility study, has some limitations as well. This study could be a basis on establishing an analysis framework that is more accurate and reasonable by comparing analytical approach and practical approach.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2493-2501
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• 2013

Various schemes of transportation demand management(TDM) to discourage the use of cars and enhance public transit performance have been implemented in large cities. Nevertheless, policy effects in reducing car have not been satisfactory. Car-dependent travelers who tend to keep driving cars regardless of the change of the trip circumstances as such increase of travel time and cost according to car use or improvement of public transit service may be due to not according to utility reflecting mode-specific impedance and their own socio-economic characteristics. In this study, travelers were classified into four groups by their choice frequency of private car and public transit in unspecified multiple trip(car-dependent, car-choice, public transit-choice, public transit-dependent class). And the characteristics of each group were comparative analyzed. The results show that the group of a higher car-dependent is a higher priority on convenience and comfortability of the car when making decisions and the group of a lower of car-dependent is likely to change to public transit.

• Journal of Korean Society of Transportation
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• v.34 no.6
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• pp.510-522
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• 2016

In studies involving public transport, social welfare improvement is simply explained by the increase in public transport demand. However, the increase in the demand for public transport is mostly observed by the change in the frequency of public transport service, and in-vehicle crowding in public transport has not been an object of concern. This study examines and tries to reveal the cause of the changes of the social welfare and in-vehicle crowding of the changing public transport from imposing congestion pricing. We observe that congestion pricing increases in-vehicle crowding in public transport. This predictable phenomenon is more exacerbated in case of not operating bus-only lane. It should be noted that in-vehicle crowding is more increased in suburban, but in First-best toll system it tends to get worse less than it in other congestion pricing systems. We identify that the change of in-vehicle crowding is affected by the change of proximity of the housing to workplace, the number of commuting trips, and unpredictable distortion effect of the congestion charge.

• Journal of Korean Society of Transportation
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• v.24 no.7 s.93
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• pp.53-62
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• 2006

The aim of this paper is to analyze the changes in the travel pattern of public transit users, service satisfaction before and after public transportation system reform in Daegu. For this purpose, we conducted a survey of people on public transit users and the results of study are as follows : First, it was found that transfer trip had increased, especially concerning the changes of travel pattern from bus trip to the transfer trip between the bus and subway. Because it makes a financial sense to transfer based on free charge transfer system. Secondly, the transfer satisfaction was improved for public transit users, but they are still reluctant to use transfer system.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.3
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• pp.1-11
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• 2023

COVID-19 has caused the dramatic reduction of public transportation demand in Busan Metropolitan City, that is, daily public transportation trips in 2020 dropped by approximately 920,000 trips from 2019 based on the public transportation card data. This study investigated the underlying factors affecting the public transportation demand discrepancy between before and after COVID-19 at the primary administration unit(i.e., Eup, Myeon, Dong) level with Ordered Logistic Regression model. Finding of this study is as follows. The primary administration units characterized with high ratio of welfare recipients, industrial area, and day boarders were heavily dependent on public transit, indicating little change in public transportation demand. On the other hands, the primary administration units which have high ratio of urban rail transit uses experienced significant reduction of public transportation demand. In conclusion, transportation policies taken under emergent situation such as COVID-19 need to take into account the region-based characteristics rather than unilateral ones.

• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.123-133
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• 2007

This study analyzed whether a transit network with hierarchy is efficient or not, and if transit network hierarchy has cost efficiency, then which condition guarantees the efficiency of the transit network hierarchy. The authors modeled the total cost of the transit network and suggested the conditions in which the transit network hierarchy has cost efficiency through comparing the cost of the transit network with and without hierarchy. The efficiency of transit network hierarchy is guaranteed when the travel cost savings induced by using a higher hierarchy transit network is larger than the increasing non-travel cost, which is the sum of access cost, waiting cost, and operating cost, induced by the introduction of a higher hierarchy transit network. This result is consistent with common sense and with the concept of cost and benefit analysis. If a passenger traveling within the area divided by a higher hierarchy transit network uses only a lower hierarchy transit network and the passenger traveling out of the area divided by the higher hierarchy transit network uses both lower and higher hierarchy transit networks, the travel demand using the higher hierarchy transit network is inversely proportional to the square of the line spacing. This means that the transit network becomes more efficient and small increases of travel demand guarantee the efficiency of the transit network hierarchy as the connectivity of the network becomes higher. This result shows that transit networks have economies of aggregation. This study is the first analytical research on transit network hierarchy and is expected to be a basis for numerical research. However, numerical research should complement this study, since analytical research has some limitations for considering a real network.

• Journal of Korean Society of Transportation
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• v.25 no.3
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• pp.137-144
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• 2007

This study involves an analytical approach to determine transit dispatching schedules (headways) Determining a time schedule is an important process in transit system planning. In general, the transit headway should be shorter during the peak hour than at non-peak hours for demand-responsive service. It allows passengers to minimize their waiting time under inelastic, fixed demand conditions. The transit headway should be longer as operating costs increase, and shorter as demand and waiting time increase. Optimal headway depends on the amount of ridership. and each individual vehicle dispatching time depends on the distribution of the ridership. This study provides a theoretical foundation for the dispatching scheme consistent with common sense. Previous research suggested a dispatching scheme with even headway. However, according to this research, that is valid for a specific case when the demand pattern is uniform. This study is a general analysis expanding that previous research. This study suggests an easy method to set a time table without a complex and difficult calculation. Further. if the time axis is changed to the space axis instead, this study could be expanded to address the spacing problems of some facilities such as roads. stations, routes and others.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.5
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• pp.1525-1534
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• 2014

In recent years, the passengers are likely to decide their route on impulse due to the development of the integrated public transport system, and real-time information system. Especially, public transport fare integration in Seoul Metropolitan area, 2004 makes them not to have resistance about changing the modes or routes and their route choice is most effected by the degree of congestion. Assignment model have limitations to describe route changes by congestion. In this study, the concept of a link cost function used in road assignment and Effective frequency is introduced to describe the passengers' behavior when the capacity of public transport is over and the waiting time variation. Two situations, new transit line operation and accident, are set up to validate the model, as a result of the transit assignment by this model, the traffic on networks is not over the capacity. It is expected that this study will be of help to reflect the various behaviors in transit assignments.