Basic Report

The Yeondo and Yeonkyuk Bridge project aims to improve the living environment of island residents and secure them the right of passage; thus, compared to the general road projects, the ripple effects on the lives of residents are expected to be relatively massive. Nevertheless, in the case of this Yeondo and Yeonkyuk Bridge project, it is difficult to secure economic feasibility, considering the expected high costs associated with such bridges as they are being evaluated using the same benefit items as the road projects.
   Therefore, this study aims to review the reliability and validity of the existing demand estimation methods used in road and sea-crossing bridge projects and to identify areas for improvement. This study also examines the impacts of such projects on the lives of island residents. We examine if there are any differences between the demand estimation results and the observed traffic volumes upon construction of the island-to-island or island-to-land bridges. It turned out that there were no issues with over-and under-estimation. In some cases, the traffic volume turned out to be higher on weekends than on weekdays, unlike the general roads, which suggests the need to estimate demand with consideration of weekend demand for travel or tourism demand.
   However, compared to the general road projects, relatively large measurement errors were used in the demand estimation for road and land-connecting bridges, but the differences were not significant. Also, the actual traffic volumes fall within the capacity of such transport infrastructure facility. When reflecting the induced demand, the generally applied demand estimation method in Korea for maritime bridges is to add 50% to the existing traffic demand. In this study, a traffic survey conducted to estimate the additional traffic generated by such a project found that an average of 55% additional traffic would be generated, all of which indicate no problem with the current method.
   This study found that regarding population movement, the opening of the Yeondo and Yeonryuk Bridges enhanced population mobility. Regarding the number of employment, employees in the agriculture, forestry, and fishery sectors decreased, whereas the number increased in the service and wholesale and retail industries, indicating the impacts on the industrial structure in that particular region.
   In addition, to examine the changes in land utility caused by the construction of the Yeondo and Yeonryuk Bridges, a Difference in Difference analysis was performed on the standard land price. It was found that the increase in land prices in the Amtaedo area, which has been connected through the Cheonsa Bridge, is relatively high compared to other areas, and this difference was statistically significant. The Cheonsa Bridge turned out to increase land prices by about 19.6%.
   We also conducted a survey about the socioeconomic changes derived from such bridge projects and found that the majority perceive a significant improvement in transportation and children's education quality with the construction of such bridges. An increase in the number of visitors, vitalization of the tourism industry, as well as an increase in income and asset value, were also reported. It was also reported that the land traffic increased due to improved accessibility and reduced travel costs. However, they expressed some concerns related to environmental issues, including damage to natural scenery caused by the construction of bridges and land-connecting bridges, and other environmental damage caused by increased tourism, etc.
   This study empirically examines the impacts of the Yeondo and Yeonkyuk bridges project on the local community, as it would be necessary to identify benefit items reflecting such impacts when conducting its economic feasibility study.
   Since the survey was conducted on two representative island regions of the west coast whose sample is not representative of all island regions in S. Korea, the findings are not generalizable. Thus, more research on various areas and cases need to be conducted. Additional measures, such as reviewing variables to secure the significance of statistical analysis results, need to be considered.
   The overall findings suggest that the bridge construction project has more positive impacts on the island residents compared to the general road project.