## 2 Criteria and Procedure for Selecting Consolidation Centers  
### Screening Criteria  
The Chinese government has issued various documents with regard to the layout of Chinese logistics center cities over recent years. These documents include: \"a plan to develop modern logistics during the 14 th Five-Year Plan period (2021-2025)\" ([[https://www.gov.cn/zhengce/content/2022-12/15/content_5732092.htm](https://www.gov.cn/zhengce/content/2022-12/15/content_5732092.htm)]([https://www.gov.cn/zhengce/content/2022-12/15/content_5732092.htm](https://www.gov.cn/zhengce/content/2022-12/15/content_5732092.htm)), accessed on 15 January 2023), \"Outline of National Comprehensive Three-Dimensional Transportation Network Plan (2021-2035)\" ([[http://finance.people.com.cn/n1/2021/0224/c1004-32036071.html](http://finance.people.com.cn/n1/2021/0224/c1004-32036071.html)]([http://finance.people.com.cn/n1/2021/0224/c1004-32036071.html](http://finance.people.com.cn/n1/2021/0224/c1004-32036071.html)), accessed on 15 January 2023), \"Outline of Building a Strong Transportation Nation (2020-2035)\" ([[https://www.gov.cn/zhengce/2019-09/19/content_5431432.htm](https://www.gov.cn/zhengce/2019-09/19/content_5431432.htm)]([https://www.gov.cn/zhengce/2019-09/19/content_5431432.htm](https://www.gov.cn/zhengce/2019-09/19/content_5431432.htm)), accessed on 16 January 2023), \"Outline of the 14 th Five-Year Plan (2021-2025) for National Economic and Social Development and the Long-Range Objectives Through the Year 2035\" ([[https://www.gov.cn/xinwen/2021-03/13/content_5592681.htm](https://www.gov.cn/xinwen/2021-03/13/content_5592681.htm)]([https://www.gov.cn/xinwen/2021-03/13/content_5592681.htm](https://www.gov.cn/xinwen/2021-03/13/content_5592681.htm)), accessed on 17 January 2023), \"Implementation Plan for Promoting the High-Quality Development of the 'Air Silk Road'during the 14 th Five-Year Plan Period (2021-2025)\" ([[http://www.caac.gov.cn/PHONE/XXGK_17/XXGK/SYZCFBJD/202205/t20220506_213121.html](http://www.caac.gov.cn/PHONE/XXGK_17/XXGK/SYZCFBJD/202205/t20220506_213121.html)]([http://www.caac.gov.cn/PHONE/XXGK_17/XXGK/SYZCFBJD/202205/t20220506_213121.html](http://www.caac.gov.cn/PHONE/XXGK_17/XXGK/SYZCFBJD/202205/t20220506_213121.html)), accessed on 17 January 2023), and so on. The publication of these different transportation plans provides policy support for the construction of transportation networks. However, these documents are primarily formulated for a single transportation mode and lack comprehensive planning for the integration of multiple modes.  
Due to factors such as economic scale, geography, and population, not every city in China is suitable as a consolidation center [11; 18]. This study constructed rules for screening the consolidation centers considering Chinese government documents, the geographical location, and the accessibility of transportation modes. Meanwhile, cities in Xizang, considering the population and economic scale, as well as Hainan, Taiwan, Hong Kong, and Macau, considering the geography and political factors, were excluded. This not only enhances the accuracy of the evaluation of the consolidation centers but also narrows down the selected cities. Considering the above-mentioned factors, with reference to [27] and [32], the specific screening criteria were formulated as follows:  
Criterion 1: Node cities linked by CR Express, highway, domestic air, and/or water transportation modes.  
Criterion 2: National- or regional-level logistics node cities.  
Criterion 3: Provincial capital city.  
Criterion 1 mainly reflects the cumulative advantages of the transportation mode of the comprehensive transportation network. Criterion 2 presents the national logistic layout, and Criterion 3 selects provincial capitals to demonstrate the support of local governments.