A comparative study on urban underground space planning system between China and Japan

In China, urban underground space (UUS) planning is still in the exploration stage, and its development is hindered by problems related to local autonomy, systemic deficiency and poor management. This paper compared and analyzed the development status of UUS planning in China and Japan to study the differences in terms of planning objectives, planning structure, and planning content of UUS, and made suggestions for the future development of China's UUS planning system. Since there are many difficulties in underground master planning in China to predict the planning scale of UUS, planning can only serve to provide planning principles and site selections. Instead, the regulatory detailed planning has legal effect in the planning system and becomes the most direct and powerful tool for the government to control and guide the urban land use. Meanwhile, Japan's underground utilization system is guided by urban agglomeration and can provide an important reference for Chinese development in terms of refined design, human concern, regulation, legislation, and coordination. Urgently, China needs to establish a system for UUS planning and management to promote three-dimensional urban development, establish coordination mechanisms for the detailed planning of UUS, and strengthen the planning of underground transportation networks, complexes, and streets.