A public-private partnership (P3) is just that: a partnership between a public agency and a private-sector entity (often called a "Concessionaire"). A P3 refers to the contractual agreement that allows the private sector entity to have greater participation in the delivery of a transportation project. Using traditional project delivery methods, ADOT bears all of the risks and responsibilities for a project. Under a P3, the private partner takes on some or all of the project's risks and responsibilities.
For roadway and bridge projects, P3s typically involve an up-front investment by a private partner who then designs, builds, finances, operates and maintains the facility in exchange for future revenues generated by the facility. These revenues typically come from tolls paid by the users of the facility. In Arizona, P3s terms can last up to 50 years unless extended by ADOT.