What motivates the collaborative innovation relationship in infrastructure projects from dynamic network perspective

The scale and complexity of infrastructure projects, involving numerous stakeholders, present significant technical challenges. To effectively address these challenges, inter-organizational collaborative innovation is essential. However, there is little research on the underpinnings of collaborative innovation relationship (CIR) in infrastructure projects from a dynamic network perspective. This study aims to explore the mechanisms driving the evolution of CIR through longitudinal data from infrastructure projects implemented in China between 2008 and 2023. CIR networks are constructed based on the Derwent Innovation Index (DII) database, and their evolutionary characteristics are analyzed via social network analysis (SNA). A multiple regression quadratic assignment procedure (MRQAP) is employed to examine determinants of CIR networks, with a specific focus on the evolution of both independent and interaction effects of proximity. The results indicate that CIR in infrastructure projects evolves into a hub-and-spoke feature across three distinct stages. Notably, the proliferation of intelligent construction technology emerges as a significant development. Enterprises serve as core players and bridges, while research institutions and universities take the leadership in innovation. Furthermore, the influence of geographical proximity on CIR networks diminishes over time, whereas social proximity becomes increasingly influential. The relationships between geographical, institutional, and organizational proximity exhibit dynamic changes, characterized by both complementarity and substitutability. These findings contribute to the existing literature on dynamic collaborative relationships among stakeholders in infrastructure projects innovation and provide practical insights for enhancing inter-organizational collaboration in such projects.