Strategies for Effective Scope Validation during Pre- and Postaward Phases in Design–Build Infrastructure Projects

In design–build (DB) projects, the design–builder is engaged before the design is fully completed, embedding unknown factors, such as subsurface conditions and design commitments, into the project. Given the limited time available for procurement, these uncertainties can amplify project risks, leading to potential cost overruns, delays, or suboptimal outcomes. Thus, scope validation is a critical process in DB projects to mitigate risks and align project goals across the pre- and postaward phases. This study examines effective risk allocation strategies and collaborative mechanisms employed by state DOTs, leveraging structured interviews, semistructured interviews, and a thematic content analysis of collected data. Consensus key practices, such as proprietary meetings and alternative technical concepts (ATCs), and emerging tools like risk registers, introduced by the Florida DOT, and optimization and refinement periods, implemented by the North Carolina DOT, are analyzed. The findings emphasize the importance of early collaboration, transparent risk allocation, and innovative procurement mechanisms to address project uncertainties. This study provides actionable insights into how state highway agencies and DB teams can work together to mitigate risks, improve project outcomes, and ensure the successful delivery of complex projects.