The urbanization and the revolution of transportation from the spread of private cars have resulted in environmental and social problems, causing urban sprawl and dependence on private cars. In order to overcome this, the integration between transport...
The urbanization and the revolution of transportation from the spread of private cars have resulted in environmental and social problems, causing urban sprawl and dependence on private cars. In order to overcome this, the integration between transportation and land use through urban policies such as Transit-oriented Development (TOD) has been discussed. Although Seoul Metropolitan Area has developed compact urban structure during urban expansion, the modal split of private cars is still increasing with a high level, and the transit services are deteriorating. In order to solve this problem and make an efficient urban structure, it is necessary to discuss for the realization of TOD for Seoul Metropolitan Area.
TOD should be realized at the metropolitan level, not just improving the performance of individual station areas. Since numerous station areas have different potential for TOD in the interrelationship between land use and transportation, it is important to identify the differences in TOD potential derived from the imbalance between land use and transportation. This process makes it possible to prioritize investment of transit infrastructure and urban development.
Therefore, this study assessed the potential for TOD in Seoul Metropolitan Area through the typology on the basis of interrelationship between nodes and places. We used node-place model to reveal the imbalance between land use and transportation, and considered both railway and rapid-bus networks according to the context of transport system in Seoul Metropolitan Area.
We conducted three stages of analysis using subvariables divided into three categories: node-, place-, and design-index. First, correlation analysis between node- and place-index was conducted. Second, five types were derived, such as 'Center TOD', 'Dense Old-town TOD', 'Dense New-town TOD', 'Rapid-bus TOD', and 'TAD(Transit-adjacent Development)', and we compared with the results of node-place model and the Central Place System in 2040 Seoul Plan. Lastly, verification of the typology results was conducted through analyzing differences in transit modal split between types. The results and implications are as follows.
First, the interrelationship between node- and place-index was revealed in Seoul Metropolitan Area, and the imbalances were mainly identified in city centers and old-town. This suggests that policies to alleviate the imbalance, such as supplying more transit services or promoting development within station areas, could contribute to the facilitation of transit in metropolitan level. It means that monitoring based on the relationship between transportation and land use is necessary.
Second, the node-place imbalances in Seoul City accorded with Central Place System on the whole, however, this result implied the importance of considering metropolitan transit network condition in urban structure policies. While supply of transit is not sufficiently keeping up with the polycentralization of urban activities, some areas are assessed as the potential TOD due to a high rapid-bus accessibility despite differences from the Central Place System. This suggests that networks of multiple transit modes should be considered to achieve TOD in urban structure policies of Seoul Metropolitan Area.
Third, TOD types possessing a high level of rapid-bus characteristics showed a higher transit modal split compared to the TAD type. Two types are identified: some areas where railways and rapid-buses are complementary to each other, and other areas where rapid-buses play a crucial role away from the railway network. It is revealed that rail- and bus-based urban structures coexist in Seoul Metropolitan area, suggesting the necessity for consideration of multiple transit modes.
Lastly, the TAD type, which is contrast to TOD, was identified to be dependent on private cars and distributed in various areas. The prospective urban sprawl could be occurred in TAD areas, and it should be considered that TOD potential differs depending on the proximity to city centers or the possibility of extending railway network. TOD policies can be feasible through mutual supplementation between rail- and bus-based networks.
It is necessary to make an effort to achieve transit-oriented development (TOD) at the metropolitan level, in order to comprehensively solve metropolitan issues such as environmental concerns, traffic problems, and housing shortages in Seoul Metropolitan Area. From that point of view, the results of this study are expected to contribute to the future urban structure policy in Seoul Metropolitan Area. Departing from the previous urban structure system centered around road networks, transit networks and polycentralization are being considered in the「2040 Seoul Metropolitan Regional Plan」. In this trend, the results of this study are expected to be used as the basis for the urban structure policy of the metropolitan regional plan and as essential data for the ongoing ‘GTX’(Great Train eXpress, new railway plans in Seoul Metropolitan Area) and urban development such as the ‘3rd New Town’ plan.