<p>The integration of local policies and national strategies for infrastructure implementation with area-based development is critical for achieving project sustainability. This study adopts the Bio–Circular–Green (BCG) economy framework - a national strategy - as a management approach to promote sustainable outcomes in area-based infrastructure projects (AIPs). The primary objective is to identify key management factors influencing the sustainability of AIPs. A mixed-methods approach, combining qualitative and quantitative methodologies, was employed. In the qualitative phase, relevant management factors were identified through a review of existing literature and selected based on their potential impact. The practical context of infrastructure projects was explored through semi-structured interviews with project managers. Additionally, to validate and refine the findings, a group discussion with five individuals whose expertise is area-based infrastructure project management was held. In the quantitative phase, a structured questionnaire was developed, tested for validity, and distributed to Local Administrative Organisations (LAOs) across Thailand. The results revealed that the total cumulative variance is explained by 62.21%, with green economy management factors accounting for the largest share of variance, followed by circular economy and bioeconomy factors. These findings provide valuable insights for enhancing BCG economy strategies, sustainability practices, and good governance in AIPs development. The results are particularly relevant for stakeholders involved in planning and developing AIPs, including project managers, developers, researchers, administrators, technicians, and operators, offering actionable recommendations to advance sustainable infrastructure practices.</p>