Approach to Determination of Risk-Based Inspection Workload for Highway Construction Projects

State departments of transportation (DOTs) are increasingly charged with developing and managing more highway construction projects while facing a substantial challenge in performing construction inspection activities with reduced resources of funding and inspection staff. Several state DOTs have applied workload reduction approaches including risk-based inspection methods to offset the shortage of inspection resources. The purpose of this study was to develop a framework to determine an appropriate inspection workload associated with construction inspection risk levels. The framework included three stages: (1) determination of project needs of inspection workforce, (2) utilizing risk-based prioritization of inspection activities, and (3) allocation of the workforce based on risk levels of inspection activities. The proposed framework was developed based on data collected from a comprehensive literature review and survey questionnaires of 50 state DOTs. The findings from this study indicated that almost all 38 responding state DOTs have a shortage of inspection staff. Four main strategies that state DOTs used to overcome the shortage of inspection workforce include outsourcing quality assurance (QA) inspections to consultants, using contractors' test results for acceptance, reducing the number of inspections and testing frequency, and prioritizing QA inspections. The framework was tested and calibrated with a case study project in Kansas. The result shows that the proposed framework can be implemented by state DOTs to increase the value of inspection with a limited workforce. The framework also allows project managers to better understand and allocate the available inspection resources to alleviate the risk of quality shortfall.