“Governments around the world are using public-private partnerships (P3s) to provide needed infrastructure. They often claim that the involvement of the private sector in the delivery of infrastructure will generate various benefits, particularly innovation. However, public agencies and private infrastructure developers provide limited evidence of innovation outcomes. While academic scholars have explored the topic, the studies are limited and have generated alternative results. This dissertation contributes to the areas of infrastructure innovation and P3s with three independent but interrelated studies. First, the exploration of the literature and the perspectives of 23 experienced project participants identified four predominant factors that influence the occurrence of innovation in P3 projects: i) risk, ii) client, iii) procurement, and iv) project type. Second, a framework to identify and classify project level technical innovations in a replicable and transparent manner was developed and tested. Lastly, a multi-case study approach was adopted to determine the types of innovation found and to assess the influence of key project characteristics on P3 project technical innovation. Project documentation was assessed and interviews were conducted with public and private participants in six contemporary U.S. highway P3 projects. Technical innovation was found within the cases, albeit limited. Demand risk and involving the private partner early were two of the most influential project characteristics on technical innovation. Further, these two characteristics promoted added-value technical enhancements through increased safety, reduced project durations, and decreased project costs.”