Cost-benefit Analysis for Route Laying Mode Decision of Beijing Metro Line 15

摘要

The route laying mode of urban rapid rail transit has important influence on urban land use and local area development. The choice between elevated line and underground line is usually controversial, especially in the area with potential development. While qualitative analysis can decide the rout laying mode in definite developed area, a quantitative evaluation considering comprehensive issues is needed to make the right decision at area with an unknown future of development. A revised costbenefit analysis is proposed in this paper with added aspects, such as cost of environmental impact and benefit of land use saving, air defence function and passenger interchanging time saving, which have more advantage for underground line. A questionnaire of environmental impact by pay willing investigation and the air defence function benefit calculation are introduced. The proposed method was used for the compare of route laying method in one section of Beijing Metro Line 15. Result of the new approach of C-B analysis show that the ratio of benefit to cost for underground line scheme is bigger than that of elevated line scheme, which is totally opposite to the result got from traditional evaluation approach. The owner and the planning bureau adopted the suggestion of the underground line scheme, which has been put into practice in the final design at the decision making research area of going underground.