Saudi Arabia's infrastructure pipeline under Vision 2030 requires project delivery systems that can manage uncertainty while improving cost, schedule, quality, safety, and stakeholder outcomes. This review paper develops an integrated risk management and process improvement model for large-scale infrastructure development in Saudi Arabia by synthesizing recent literature on risk governance, lean construction, BIM-enabled coordination, digital twins, data analytics, sustainability, and public-private delivery. The study uses a structured narrative review supported by PRISMA-informed screening logic and thematic synthesis of research published mainly between 2020 and 2025. The review finds that traditional risk registers and periodic reporting are insufficient for giga-project environments because risks evolve across interfaces, procurement packages, regulatory approvals, community expectations, and operational readiness. A more effective approach connects enterprise risk governance with process improvement cycles, real-time control data, predictive analytics, collaborative decision-making, and lessons-learned loops. The proposed model positions risk management not as a compliance activity but as a continuous performance system that links strategic objectives to delivery baselines, risk intelligence, corrective action, and institutional learning. The framework is termed the Integrated Risk and Process Governance Framework for Saudi Infrastructure Projects (IRPGF-SIP). The paper contributes a Saudi-specific framework that supports Vision 2030 infrastructure objectives by integrating proactive risk identification, standardized process controls, digital assurance, and adaptive governance across the project lifecycle.