Critical Risk Factors in Project Delivery Method Selection for Highway Projects

Selecting an appropriate project delivery method is a complex decision-making process due to risks and uncertainties. At the time of the decision, the owner and stakeholders often have little information and the project plans are not detailed enough to make a judgment about the project with certainty of outcomes. This paper examines 39 risk factors related to the project delivery selection process. These risk factors were identified through completed cost and schedule risk analysis on more than $100 million of highway projects. A questionnaire was developed to collect the data a cross section of three delivery methods, including design-bid-build, designbuild, and construction manager/general contractor. Experts with an average of 25 years of related experience were invited to participate in the survey. The results indicate that the four risk factors that have most influence to all three delivery methods are: unexpected utility encounter; third-party delays during construction; geotechnical investigation; and delays in reviewing and obtaining environmental approvals. The research identified five other risk factors that have varying impacts on project delivery selection constructability of design; delivery schedule; railroad agreements; obtaining other agency approvals; and scope definition. This study also discusses the pertinent findings and rationale behind the critical risk factors.