The Parliament's Standing Committee on Transport and Communication decided in Februry 2007 to procure a state-of-the-art report with respect to Public Private Partnerships (PPP). The purpose was to let committee members share experiences and research results from PPP projects that have been implemented elsewhere in Europe and overseas, well before that the Parliament is to take a decision on the future use of such contracts in spring 2008. VTI was commissioned to do this job, and the present report provides the conclusion from the mission. The document demonstrates that a transfer from today's model for paying for infrastructure - i.e. that the public sector budget is paying all costs during the year(s) that an investment is built - to a PPP model and thereby making down-payments from the budget over a contract period to pay for the costs, creates some scope for increased spending in this or other sectors during a transition period. The possibility to spend extra will, however, gradually shrink once the volume of down-payments grows. PPP is therefore not a new instrument for infrastructure financing. Provided that the contract between the public sector procurer and the private sector agent (the entrepreneur) is appropriately crafted, PPP may however improve cost efficiency in the construction industry. This is particularly pertinent in view of the industry's weak productivity performance, with virtually zero growth of output per hour of labour input during the last ten years. The few ex post studies that have been made of the outcome of PPP indicate that such projects are built on time or even opened before schedule, and that cost overruns are fewer than for standard projects. It has however been difficult to document actual cost savings. The report identifies a number of aspects that should be accounted for when the contract between the public and private sector is designed.