**8. Conclusions**

Considering the various influencing factors on HSR sustainability, this paper created an evaluation index system from four primary aspects: process, economic benefits, effect, and sustainability. Then, the unascertained measure was introduced for comprehensive evaluation. The main conclusions and innovation points of this research are listed as follows.


All in all, this research lays a solid basis for the sustainability evaluation of HSR construction projects and simplifies the modelling process for designers of HSR.

**Acknowledgments:** The authors gratefully acknowledge financial support from National Science and Technology Basic Work of Special Key Projects (2017FY10130), supported by National Natural Science Foundation of China (41511130033), supported by Research project of the Chinese Academy of Sciences (Y66Q034).

**Author Contributions:** This paper presents a team work research result written by the co-authors, Yongzhi Chang, Yang Yang, and Suocheng Dong. Suocheng Dong conceived and designed the study; Yongzhi Chang and Yang Yang analyzed the HSR construction project the data. With cross discussions of the research results, the co-authors have contributed substantially to the work reported.

**Conflicts of Interest:** The authors declare no conflict of interest.
