A PPP is not merely the outsourcing of transit system services and functions to the private sector but involves a partnership relationship between the sponsor transit agency and the private partner whereby each provides those services it is best equipped to offer in the most cost-effective manner - not merely the cheapest. PPPs bring specialized resources to a transit service operation that can significantly leverage the resources and capabilities of the sponsor transit agency. These improved practices result in better patron service, greater access to capital markets to expedite project delivery by augmenting more traditional sources of funding and finance, quicker access to more efficient technology, and in certain instances less expensive staff resources to perform functions only when needed instead of retaining them on a full-time basis.
PPPs also introduce competition to the provision of public transportation facilities and services, which inevitably serves to increase the availability of qualified resources to perform these functions and places downward pressure on the prices of these services, especially when there are multiple providers to choose from. Alternatively, private sector involvement can result in service quality improvements at the same cost as traditional public agency-provided services, but with the potential for the added benefit of transferring the risk of providing the desired service quality to the private partner.
The public sponsor agency also serves to protect the public interest in the social benefits and externalities provided by public transportation services.