Examination of Project Duration, Project Intensity, and Timing of Cost Certainty in Highway Project Delivery Methods

Although agencies design and construct the vast majority of federally funded highways through the traditional design-bid-build (DBB) method, the use of construction manager/general contractor (CM/GC) and design-build (DB) is increasing. Previous research articles on the performance of these delivery methods include projects of different characteristics and projects from different sectors. This study examined solely US highway projects through a unique analysis of comparable projects. This study compared the project delivery methods that are frequently used in two separate cost pools, $2 million to $10 million and $10 million to $50 million. In the cost pool of $2 million to $10 million, the delivery methods of DBB and low-bid-procured DB (DB/LB) were compared. The delivery methods of DBB, CM/GC, and best-value-procured DB (DB/BV) were compared in the cost pool of $10 million to $50 million. The results show that the alternative contracting methods of CM/GC and DB are superior to the traditional DBB method for the performance metrics of project duration, project intensity, and timing of cost certainty in both cost pools. In comparing the alternative contracting methods in the $10 million to $50 million cost range, the CM/GC method was found to outperform DB/BV, which has not yet been shown in the research literature. With pressure on state transportation agencies to be efficient with funds, the alternative contracting methods are viable options for shortening project durations, establishing early cost certainty during project delivery, and delivering projects at a more intense pace. The findings presented are useful for practitioners to better understand how project delivery methods can meet their needs for US highway construction. (C) 2018 American Society of Civil Engineers.