PURPOSES : This study aimed to improve the effect of increasing the number of urban railway users when public transportation accessibility is improved by using village buses. METHODS : Using the case of Daejeon City, this study utilized the greenhouse gas reduction benefit among the benefits of the investment evaluation guidelines of the Ministry of Land, Infrastructure and Transport to demonstrate the effect of introducing village buses, a flexible means of transportation, to transportation-disadvantaged areas and improving accessibility, thereby inducing a change to urban railways. and were quantitatively analyzed. RESULTS : The number of users expected to switch to urban rail was 9,964 in 2020 and 9,220 in 2025. Thus, the greenhouse gas reduction effect is predicted to decrease annually by 34,554 t (2020) and 31,973 t (2025). CONCLUSIONS : Among the demand management techniques, reducing the use rate of passenger cars is one of the most important. For this policy, it is most effective to provide an alternative means of transportation.

In order to meet the national standard and public needs for Seoul Metro subway, air purification has been taken into a consistent consideration with the addition of high quality control facilities. This work focuses on the review of the cost effectiveness to improve the air filtration of an MVAC (mechanical ventilation & air conditioning) in a field subway. The inflow PM₁₀ and PM_2.5 into the test MVAC chamber were 19.4 kg/yr and 8.9 kg/yr respectively. It corresponds to the environmental cost of 5,857,000 won for PM₁₀ and 6,608,000 won for PM_2.5 every year. While the current filtration system collects approximately 55% of the inlet PM₁₀ and 35% of PM_2.5, a new lay-out showed 80% for PM₁₀ and 55% for PM_2.5. The new design presented the environmental benefit for PM10 with 1,464,000 won, whilst the additional cost required 3,192,744 won. In the future, however, the increase of environmental benefits for the indoor dust over the atmospheric aerosols will more or less compensate the potential cost.

Recent urban sprawl has destroyed various kinds of green space in the city. It has affected quality of people’s life in the city, as well as urban ecosystem. Recent study shows the possibilities of roofs as green spaces in urban central site where the land costs are generally high. This research focuses on Jung-Gu district in Daegu Metropolitan city as a study area and calculates possible area of green roof using 2002 Autocad program based on aerial photographs and land registration maps. And the purpose of this research is to analyze environmental and economic effects of green roof. The environmental effects are as follows. It is expected that 91,106 ㎡ green spaces, 12.13 % of study site, will be added if green roof is performed in the study site. It is assumed that the expanded areas could reduce the highest temperature to 0.5-1.0 ℃ during the summer in terms of environmental effect. And the following shows the economic effects. If green roof and greening urban central site are created as a same size of 91,106 ㎡, it will be expected that the costs of green roof will be much more inexpensive than about 98 billions won. It will be also found that the expense of cooling energy can be saved out about 8 millions won per day in summer, if grass planting is accomplished on the possible areas of green roof in the study site. Therefore, it is desirable to take legal supports such as enacting regulations to activate green roof for more environmental and economic effects. For instance, green roof for public institutions, school and model area selection are desirable method to publicize the effect of greening program for citizen's participation.