{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,19]],"date-time":"2025-11-19T15:09:31Z","timestamp":1763564971899,"version":"3.45.0"},"reference-count":62,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,11,19]],"date-time":"2025-11-19T00:00:00Z","timestamp":1763510400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Engineering Laboratory of Integrated Transportation Big Data Application Technology"},{"name":"the Natural Science Foundation of Sichuan Province","award":["24NSFSC0356"],"award-info":[{"award-number":["24NSFSC0356"]}]},{"name":"the Science & Technology Project of Sichuan Province","award":["2020YJ0255"],"award-info":[{"award-number":["2020YJ0255"]}]},{"name":"the Science Project of Chengdu","award":["2019-RK00-00016-ZF"],"award-info":[{"award-number":["2019-RK00-00016-ZF"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>In the absence of system-wide planning and coordination, emerging mobility services have been integrated into urban transportation systems as independent network layers. Meanwhile, their interactions with traditional public transit give rise to complex self-organizing patterns in population mobility, manifested as coopetitive dynamics. To systematically analyze this phenomenon, this study constructs a four-layer temporal network\u2014consisting of ride-hailing, metro, combined, and potential layers\u2014based on a vectorized multilayer network model and inter-layer mapping relationships. An analytical framework is then developed using node strength, cosine similarity, and rich-club coefficients, along with two newly proposed indicators: the intermodal index and the node importance coefficient. The results reveal, for the first time, a spontaneously emergent intermodal phenomenon between ride-hailing and metro networks, manifested through both cross-day modal substitution and intra-day intermodal chains. The analysis further demonstrates that when sufficiently large and homogeneous demand cohorts are present, the phenomena can emerge even on non-working days. Based on the characteristics of this phenomenon, a method has been developed to identify intermodal nodes across different transport networks. Furthermore, the study uncovers a time-varying multicentric hierarchical structure within the metro network, characterized by small-scale core rich nodes and larger-scale secondary rich-node clusters. Overall, this study provides novel insights into the formation, coordination, and optimization of intermodal urban transport networks.<\/jats:p>","DOI":"10.3390\/e27111169","type":"journal-article","created":{"date-parts":[[2025,11,19]],"date-time":"2025-11-19T15:03:15Z","timestamp":1763564595000},"page":"1169","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Unveiling Self-Organization and Emergent Phenomena in Urban Transportation Systems via Multilayer Network Analysis"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-0216-1076","authenticated-orcid":false,"given":"Hongqing","family":"Bao","sequence":"first","affiliation":[{"name":"National Engineering Laboratory of Integrated Transportation Big Data Application Technology, Chengdu 611756, China"},{"name":"School of Transportation and Logistics, Southwest Jiaotong University, Chengdu 611756, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7598-2203","authenticated-orcid":false,"given":"Xia","family":"Luo","sequence":"additional","affiliation":[{"name":"National Engineering Laboratory of Integrated Transportation Big Data Application Technology, Chengdu 611756, China"},{"name":"School of Transportation and Logistics, Southwest Jiaotong University, Chengdu 611756, China"}]},{"given":"Xuan","family":"Li","sequence":"additional","affiliation":[{"name":"National Engineering Laboratory of Integrated Transportation Big Data Application Technology, Chengdu 611756, China"},{"name":"School of Transportation and Logistics, Southwest Jiaotong University, Chengdu 611756, China"}]},{"given":"Yiyang","family":"Zhao","sequence":"additional","affiliation":[{"name":"National Engineering Laboratory of Integrated Transportation Big Data Application Technology, Chengdu 611756, China"},{"name":"School of Transportation and Logistics, Southwest Jiaotong University, Chengdu 611756, China"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1007\/s13194-012-0056-8","article-title":"What is a complex system?","volume":"3","author":"Ladyman","year":"2013","journal-title":"Eur. 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