The first key characteristic of a PPP project is its mission. This includes public sector goals and objectives for the project-focused on its intended results and public benefit-and, following from that, the kind of facility and public service to be provided. These policy decisions then will determine whether a PPP is appropriate or feasible and, if so, the project delivery structure and financing tools to be considered.
Projects with many different missions may be deliverable through PPPs. This report focuses on PPPs for transportation projects-especially highways-but these partnerships have been used in many sectors worldwide, including building or modernizing schools, hospitals and other health care facilities, traditional and renewable energy projects, water and wastewater utilities, government buildings, prisons, police and fire stations, and national defense projects. In the transportation sector, PPPs can help deliver diverse highway and bridge, rail, mass transit, aviation, ferry and port projects. PPPs are not appropriate for every project, however; in fact, less than 20 percent of transportation infrastructure is likely to be deliverable through PPPs (see also Principle 6).12
One significant difference among PPPs in terms of mission lies between projects that develop new infrastructure ("green-field" projects) and those that operate, maintain, preserve or improve existing infrastructure ("Brownfield" projects). Blended greenfield - brownfield projects also exist-for example, adding new high-occupancy toll lanes to an existing highway to increase its capacity.13 For a pure brownfield project, appropriate PPP project structures are limited to those in which a private contractor assumes responsibility for operations and maintenance; these structures include long-term operations and maintenance (O&M) contracts or lease concessions (see Glossary). Many more project delivery models are available for greenfield projects, depending on which responsibilities are transferred to the private sector.14 Most transportation PPPs in the United States have been greenfield projects, several of which are located in Texas (see Appendix G).