method very similar to BOOT except that there is no actual ownership transfer. Moreover, the contractor assumes the risk of financing until the end of the contract period. The owner then assumes the responsibility for maintenance and operation. This model is extensively used in specific infrastructure projects such as toll roads. The private construction company is responsible for the design and construction of a piece of infrastructure for the government, which is the true owner. Moreover, the private entity has the responsibility to raise finance during the construction and the exploitation period. Usually, the public sector begins payments to the private sector for use of the asset post-construction. This is the most commonly used model in the EU according to the European Court of Auditors. Design–build–operate–transfer (DBOT) This funding option is common when the client has no knowledge of what the project entails. Hence the project is contracted to a company to design, build, operate, and then transfer it. Examples of such projects are refinery constructions. Design–construct–manage–finance (DCMF) A private entity is entrusted to design, construct, manage, and finance a facility, based on the specifications of the government. Project cash flows result from the government's payment for the rent of the facility. Some examples of the DCMF model are prisons or public hospitals. Trends in delivery method prevalence Though DBB is now used for most private projects and the majority of public projects, it has not historically been the predominant delivery method of choice. The master builders of centuries past acted both as designers and constructors for both public and private clients. In the United States, Zane's Post Road in Ohio and the IRT in New York City were both originally developed under more integrated delivery methods, as were most infrastructure projects until 1933. Integrated Project Delivery offers a new delivery method to remove considerable waste from the construction process while improving quality and a return to more collaborative methods from the past. In an effort to assist industry professionals with the selection of appropriate project delivery systems, construction management researchers have prepared a Procurement Method and Contract Selection Model, which can be used for high level decision making for construction projects on a case-by-case basis. Conceptual differences between delivery methods There are two key variables which account for the bulk of the variation between delivery methods: The extent of the integration of the various service providers. The extent to