Public-private partnerships (PPPs) have become a significant global phenomenon and governments are utilizing them more frequently to deliver projects that satisfy increasing societal demands in infrastructure sectors such as highways. Compared to traditional project delivery approaches, PPPs are long-term contracts between the public and the private sectors, where the private sector is engaged in more project tasks and accepts more risks. However, due to their long-term and complex nature, PPP contracts face many issues. Consequently, each project's contract becomes vital to project success because it: allocates risks, governs project relationships, and can align parties' interests. This dissertation examined 21 project contracts in the US highway PPP market to investigate risk allocation; contract designs and risk sharing mechanisms; and revenue risk guarantees. Using a content analysis framework, the allocation of 31 risks associated with highway PPPs was determined. These risks were mostly transferred to the private sector or shared between public and private parties, and project context had a significant influence on risk allocation. Assessment of contract designs indicated that the public sector imposes extensive monitoring and retains a majority of the decision rights to preclude opportunistic actions by the private sector; further, risk sharing mechanisms were complex and largely dependent on resolution during project implementation, which likely increases ex post transaction costs. Finally, revenue guarantees, commonly structured as standard options to mitigate revenue risk, were redesigned to incorporate exotic option features; quantitative analysis revealed that exotic structures can better serve chief PPP stakeholders' interests through increased robustness and flexibility.