Spatio-Temporal Changes and Influencing Factors of the Travel Network on China's National Day Holiday under COVID-19

COVID-19 has tremendously impacted the travel habits of urban residents. This study used the “node-line segment-network” hierarchy and Baidu migration big data to conduct a comparative analysis of the travel network patterns of urban people on China's National Day holiday before and during the COVID-19 outbreak (i.e., 2019 and 2021). The results revealed four interesting patterns: (1) In 2021, there was an increase in the aggregation coefficient and access to the intra-provincial linkage network, indicating a higher degree of the travel agglomeration of residents under the pandemic. (2) In 2021, the “hub-and-spoke” pattern on the national scale, the “core-edge” pattern of the intra-provincial scale and the “rhomboidal” structure of the extra-provincial scale were more contracted, aggregated, and low-value. (3) The coverage of the urban advantageous association decreased while the total numbers of urban clusters and single provincial clusters increased, reaching 25 and 16, respectively. This indicates that the pandemic intensified the effect of administrative boundaries as a barrier. (4) The primary determinants of movement during the pandemic were urban competition, policy control, administrative boundary barriers, and the travel intentions of residents.