External Benefit Assessment of Urban Utility Tunnels Based on Sustainable Development

Urban utility tunnels (UUTs) can have great external benefits in terms of social and environmental aspects for the sustainable development of a city. However, the high initial construction cost has been the main obstacle to the promotion of UUT projects for a long time. Although several evaluation methods for the benefits of UUTs have been proposed, most of them focus on the cost assessment during the construction period and are limited in terms of their scientificity, the feasibility of the valuation methodology and the comprehensiveness of external categories. The external benefit assessment of UUTs during their service life remains lacking, leading to an incomplete insight into UUT projects. Therefore, a scientific evaluation method of the long-term external benefits of UUTs is still needed from the perspective of urban sustainable development. This paper proposes a composite market price method to carry out a simple but systematic evaluation of the positive externalities of UUTs in monetary terms. Detailed instructions on the operation of the method are also elucidated to further improve its practicability. The feasibility and validity of the method is then demonstrated through a case study of the UUT project in Xiong’an New Area, China. It is also concluded that UUTs can benefit all social subjects and that a classification of externalities based on different social subjects can foster better development and broader support for the implementation of UUTs.