The role of public authorities in the development of infrastructure is evident. Increasingly, private parties show interest in infrastructure projects, The relationship between public and private parties can take various shapes. From a theoretical point of view, four models of co-operation between public and private parties are discussed, The realisation of the second Maasvlakte, a large scale port expansion in Rotterdam, will serve as an example. The project started in the early 1990s as a traditional (unilateral) port planning procedure. Private involvement enters the picture for the f~st time in 1998, A constructing f~ container handling company and financial institution launched the Binnenmeerplan, This innovative private initiative introduced the concept of a phased construction of the second Maasvlakte, Simultaneously, the Dutch government carried out a study project and the Combination model, which incorporates both the objectives of public parties and of the business community was developed, The Combination model can be perceived as a breakthrough because it demonstrates that solutions for problems such as existing planning procedures and EU directives can be found, Albeit the enthusiasm from both parties was overwhelming, the government exchanged the Combination model for the Parallel model. In this model, the role of central government is restricted to spatial planning and land use, regional and local government will act as project developer. At the moment two arguments in the discussion prevail: innovation and risk sharing. Therefore, parts of the project will be put on tender: Design Build Finance and Maintain (DBFM)-arrangements for the dikes and Build Operate and Transfer (BOT)-contracts for the terminals, However, it is at least doubtful whether BOT-contracts will work in the Hamburg - Le Havre range.