Design-Build for Transportation Projects: Cost and Schedule Change Performance Analysis

Design-build (DB) is an alternative project delivery method that has been used to great effect in transportation project delivery. Measuring the performance of DB projects has been the subject of many research studies. However, the collective results of these studies are difficult to interpret because they extend over decades. This paper seeks to synthesize the past 20 years of DB transportation performance literature, collect data from 47 public DB transportation projects, and compare performance results with those published in the literature. Statistical comparisons are made between the collected DB data and the transportation DB literature in order to determine if there are any performance differences in this new data set versus previously published literature. Results from the performance analysis show that DB has a median cost change of 4% and a median schedule change of zero. This study contributes to the body of knowledge by analyzing project data from 47 public DB transportation projects and combining performance outcomes with two decades of published DB performance transportation literature. The findings consistently show that DB can offer superior performance compared with the traditional design-bid-build method.