• Proceedings of the KSR Conference
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• 2005.11a
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• pp.510-515
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• 2005

Since 1974, the first subway is constructed in Seoul metropolitan area, from 1985 country metropolitan subways have been built. But most country metropolitan subways cannot reach the goal of transportation sharing ratio and show a loss. In this paper, I investigate the issues of country metropolitan subways and present the methods to improve them focusing on strengthening transit network. At first, it is introduced that the method can complement incomplete network from insufficient subway lines. And I propose the consolidation method using KORAIL railway lines. Finally, the connecting method into subway missing area is presented with various transit systems like BRT, Guideway Bus and single railway line extension.

• Journal of Urban Science
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• v.9 no.1
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• pp.33-40
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• 2020

This research aims to analyze the determinants of apartment rents in the Seoul Metropolitan area using spatial econometrics approaches. Since spatial econometrics approaches have advantages to solve limitations of ordinary multiple regression such as spatial dependence and spatial heterogeneity. This research includes structural variables such as number of rooms and baths, neighborhood variables such as number of housing units in the apartment complex, and location variables including distances to subway stations, to traditional markets, to educational institutes, and to urban services such as parks, etc. The result shows that the accessibilities to the CBD, to subcenters, to subway station, to school, and to parks contribute to apartment rent uplift and also shows different spatial variations in rent premiums by accessibility variables. In particular, apartments located south of Han river along the Lines 2, 3, 7 and 9 have the highest rent premiums due to the accessibility to the subway.

• Journal of Information Technology Services
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• v.19 no.2
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• pp.125-138
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• 2020

Currently, subway crowding is estimated by observing a specific point at specific hours once or twice every 1 or 2 years. Given the extensive subway network in Seoul Metropolitan Area covering 588 stations, 11 lines and 80 transfer stations as of 2017, implementing crowding mitigation policy may have its limitations due to data uncertainty. A proposal has recently been made to effectively use smart card data, which generates big data on the overall subway traffic related to an estimated 8 million passengers per day. To mitigate subway crowding, this study proposes two viable options based on data related to smart card used in Seoul Metropolitan Area. One is to create a subway passenger pattern model to accurately estimate subway crowding, while the other is to prove effectiveness of early bird policy to distribute subway demand that is concentrated at certain stations and certain time. A subway passenger pattern model was created to estimate the passenger routes based on subway terminal ID at the entrance and exit and data by hours. To that end, we propose assigning passengers at the routes similar to the shortest routes based on an assumption that passengers choose the fastest routes. In the model, passenger flow is simulated every minute, and subway crowding level by station and line at every hour is analyzed while station usage pattern is identified by depending on passenger paths. For early bird policy, highly crowded stations will be categorized based on congestion level extracted from subway passenger pattern model and viability of a policy which transfers certain traveling demands to early commuting hours in those stations will be reviewed. In particular, review will be conducted on the impact of policy implemented at certain stations on other stations and lines from subway network as a whole. Lastly, we proposed that smart card based subway passenger pattern model established through this study used in decision making process to ensure effective implementation of public transport policy.

• Journal of the Economic Geographical Society of Korea
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• v.19 no.3
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• pp.423-436
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• 2016

In a densely developed metropolitan area, the subway system is often constructed to address the mobility problems. Subway system was first introduced in Seoul in late 1970s, then Korean metropolitan cities began to adopt the system later. Subway systems not only resolve the mobility problems, but also interact with regional socioeconomic landscape. This study aims to find the association between the subway network and land rent within the subway catchment areas in Gwangju metropolitan city in a spaciotemporal framework. The analysis results indicated that proximity to the subway station and the size of nearest road were positively associated with the land rent. Also from a cluster analysis, it was found that the old and new Central Business Districts as well as stations at peripheral areas had distinctive land rent change characteristics. This empirical analysis indirectly proves the strong association between land rent and urban planning and also the positive relationship between land rent and transportation networks.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.3
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• pp.343-357
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• 2012

The Seoul metropolitan subway system can be represented by a graph which consists of nodes and edges. In this paper, we study classification of subway stations and trip behaviour of subway passengers through partitioning the graph of the subway system into roughly equal groups. A weight of each edge of the graph is set to the number of passengers who pass the edge, where the number of passengers is extracted from the transportation card transaction database. Since the graph partitioning problem is NP-complete, we propose a heuristic algorithm to partition the subway graph. The heuristic algorithm uses one of two alternative objective functions, one of which is to minimize the sum of weights of edges connecting nodes in different groups and the other is to maximize the ratio of passengers who get on the subway train at one subway station and get off at another subway station in the same group to the total subway passengers. In the experimental results, we illustrate the subway stations and edges in each group by color on a map and analyze the trip behaviour of subway passengers by the group origin-destination matrix.

• Particle and aerosol research
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• v.18 no.2
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• pp.23-35
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• 2022

Recently, passengers using public transport are concerned about the effects of COVID-19 and fine dust. Therefore, from February 2020 to February 2021, we investigated whether SARS-CoV-2 RNA was detected even after disinfection in 55 public transportation places visited by confirmed patients in Seoul. 34 air samples and 702 object surface samples were collected and tested with RT-PCR, one surface sample was positive. In addition, preemptive investigations were conducted in 22 subway trains that passengers were being on board at that time. 1,018 preemptive tests were performed, and all were negative. Although PM-2.5 is dangerous in itself, it can be a potential carrier of viruses. It seemed that a solution was needed as one line continuously exceeded the criteria of PM-2.5. Through this study, it is judged that cluster infection in public transportation can be prevented if efforts to reduce the concentration of fine dust, appropriate disinfection management, and personal disinfection such as wearing a mask in public transportations.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.5
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• pp.543-553
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• 2010

Almost five million citizens a day are using subways as a means of traffic communication in the Seoul metropolitan. As the subway system is typically a closed environment, indoor air pollution problems frequently occurs and passengers complain of mal-health impact. Especially $PM_{10}$ is well known as one of the major pollutants in subway indoor environments. The purpose of this study was to compare the indoor air quality in terms of $PM_{10}$ and to quantitatively compare its source contributions in a Seoul subway platform before and after installing platform screen doors (PSD). $PM_{10}$ samples were collected on the J station platform of Subway Line 7 in Seoul metropolitan area from Jun. 12, 2008 to Jan. 12, 2009. The samples collected on membrane filters using $PM_{10}$ mini-volume portable samplers were then analyzed for trace metals and soluble ions. A total of 18 chemical species (Ba, Mn, Cr, Cd, Si, Fe, Ni, Al, Cu, Pb, Ti, $Na^+$, $NH_4^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, and ${SO_4}^{2-}$) were analyzed by using an ICP-AES and an IC after performing proper pre-treatments of each sample filter. Based on the chemical information, positive matrix factorization (PMF) model was applied to identify the source of particulate matters. $PM_{10}$ for the station was characterized by three sources such as ferrous related source, soil and road dust related source, and fine secondary aerosol source. After installing PSD, the average $PM_{10}$ concentration was decreased by 20.5% during the study periods. Especially the contribution of the ferrous related source emitted during train service in a tunnel route was decreased from 59.1% to 43.8% since both platform and tunnel areas were completely blocked by screen doors. However, the contribution of the fine secondary aerosol source emitted from various outside combustion activities was increased from 14.8% to 29.9% presumably due to ill-managed ventilation system and confined platform space.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.2
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• pp.164-172
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• 2015

Seoul subway plays an important part for the public transportation service in Seoul metropolitan area. As the subway system is typically a closed environment, frequent air pollution problems occurred and passengers get malhealth impact. Especially particulate matters (PM) is well known as one of the major pollutants in subway environments. The purpose of this study was to compare the concentrations of $PM_{10}$ and $PM_{2.5}$ in the Seoul subway system and to provide fundamental data in order to management of subway system. $PM_{10}$ and $PM_{2.5}$ samples were collected in the M station platform and tunnel of Subway Line 4 in Seoul metropolitan and in an outdoor location close to it from Apr. 21, 2010~Oct. 27, 2013. The samples collected on teflon filters using $PM_{10}$ and $PM_{2.5}$ mini-volume portable samplers and PM sequential sampler. The PM contributions were $48.6{\mu}g/m^3$ (outdoor), $84.6{\mu}g/m^3$ (platform) and $204.8{\mu}g/m^3$ (tunnel) for $PM_{10}$, and $34.6{\mu}g/m^3$ (outdoor), $49.7{\mu}g/m^3$ (platform) and $83.1{\mu}g/m^3$ (tunnel) for $PM_{2.5}$. The $PM_{10}$ levels inside stations and outdoors are poorly correlated, indicating that $PM_{10}$ levels in the metro system are mainly influenced by internal sources. In this study, we compared PM concentrations before and after operation of ventilation and Electrostatic Precipitator (EP). Despite the increased PM concentration at outdoor, $PM_{10}$ concentration at platform and tunnel showed the 31.2% and 32.3% reduction efficiency after operation the reduction system. The overall results of this study suggest that the installation and operation of the ventilating system and EP should have served as one of the important components for maintaining the air quality in the subway system.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.3
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• pp.316-323
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• 2010

We propose a method to find flows of transit users in the subway transportation network of the metropolitan Seoul and analyze the passenger flows on some central links of the network. The transportation network consists of vertices for subway stops, edges for links between two adjacent subway stops, and flows on the edges' Each subway transit user makes a passenger flow along edges of the shortest path from the origin stop to the destination stop in his trip. In this paper, we have developed a new algorithm to find the passenger flow of each link in the subway network from a large trip-transaction database of subway transit users. We have applied the algorithm to find the passenger flows from one day database of about 5 million transactions by the subway transit users. As results of the experiments, the travel behavior on 4 central subway links is analyzed in passenger flows and top 10 flows among all subway links are explained in a table.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.160-171
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• 1998

Express subway system is one of the effective systems adapting to improve service level. Express trains make fewer passenger stop, using a double track or a bypass track, than local trains which served all stations, Express service has been very popular with passengers who travel uninterrupted between terminals, but is has generated some dissatisfaction among passengers who experience longer waiting time on stations. This study aims at proposing the methodology to analyze changes of travel pattern in subway system adapting the express service and to estimate the time saving effects resulting from the installation of the express system. This methodology is evaluated in the fifth line under an assumpt ion that express subway system are adapted. Based on the results of the case study, the following conclusions are made: First, express system reduce a total travel time of 13% or above. Second, shorter headway of express trains increases the time saving effects on subway system. although it requests more waiting time to local train passenger. Third, an installation of Express system to Seoul subway system can augment subway demand in seoul metropolitan area.