This research seeks to explore the determinants influencing private vehicle owners’ readiness to adopt Mobility as a Service (MaaS) through the lens of the Value-based Adoption Model (VAM). Additionally, it examines the moderating role of attitude in shaping the relationship between attitude and the intention to use MaaS. The study employs partial least squares structural equation modeling (PLS-SEM) to validate the proposed model. Data were collected through a survey of 355 private vehicle owners, focusing on their travel habits and openness to adopting MaaS. The findings indicate that perceived value, shaped by MaaS digital platform expectations, social influence, and perceived enjoyment, plays a central role in driving adoption. Conversely, perceived sacrifices, including privacy risk and perceived fees, significantly hinder adoption intentions. Trust, influenced by structural assurance and reputation, emerged as a critical determinant of both attitude and behavioral intention, while environmental consciousness moderates the relationship between attitude and intention, highlighting the importance of sustainability in user decisions. The study contributes to theoretical advancements by integrating socio-psychological and structural factors into VAM and offers practical insights for policymakers and MaaS providers to enhance adoption through trust-building, affordability, sustainability, and user-friendly platform design. These findings provide a roadmap for addressing the challenges of MaaS adoption and promoting sustainable urban transportation systems.