State-of-practice for risk-based quality assurance in state departments of transportation

Purpose: Selecting an optimal quality assurance (QA) process can have significant implications on the long-term durability and lifecycle costs of transportation projects. Currently, the approaches used by state departments of transportation (DOTs) to optimize QA are undocumented and the impact of project-specific factors are unknown. The paper aims to discuss these issues. Design/methodology/approach: State-of-practice was documented via a review of DOT guidance documents, standard specifications and minimum sampling and testing requirements; a survey of 58 state DOT representatives; and interviews with eight DOTs. Findings: DOT approaches to QA management are very diverse but can be organized into five levels that range from ad hoc visual inspection of materials to DOT-managed sampling and testing. Project size, location and complexity have strong influence on the selection of a QA approach, but DOT demographics and project delivery method are less significant. Practical implications: Present approaches to the selection of a QA approach are generally informal, subjective and do not involve formal risk analyses. A data-driven approach for transportation projects is clearly needed. Originality/value: Understanding how state DOTs approach QA method selection will serve as a foundation for new methods of QA optimization.