The integration of Value Stream Mapping (VSM) and Building Information Modeling (BIM) holds significant potential for improving efficiency, collaboration, and sustainability in road design projects. Despite the increasing adoption of Lean Construction (LC) and digital technologies in the construction sector, limited research has explored the combined application of VSM and BIM in infrastructure design, particularly for road projects. This study aims to address this gap by identifying the critical success factors (CSFs) that enable successful VSM-BIM integration in road design processes. A systematic literature review (SLR) was conducted using PRISMA 2020 guidelines, followed by a reflexive thematic analysis of five thematically relevant peer-reviewed articles published between 2014 and 2024. The findings reveal fifteen CSFs organized into five interrelated themes: Leadership and Organizational Support, Collaboration and Early Stakeholder Engagement, Process Efficiency and Waste Reduction, Technology Enablement and Visualization, and Training and Knowledge Sharing. These themes form a comprehensive framework that highlights the organizational, technical, and human enablers necessary for Lean-BIM adoption. The study contributes to both academic discourse and industry practice by providing structured insights into the integration of Lean and digital methodologies in road infrastructure projects. It also offers practical recommendations for policymakers and project managers seeking to enhance design efficiency and project delivery outcomes through VSM-BIM integration.