The literature documents several alternative approaches to partnerships (U.S.DOT 2004; AECOM 2007b; FHWA 2007; Pakkala et al. 2007). The approaches relevant to highway infrastructure are summarized in Table 1, and are sorted by involvement to the private sector, from least to greatest. The first, Design-Bid-Build (DBB) is the traditional method of project delivery; the last two are considered complete privatization, whereas the rest are considered PPP. Build-Own-Operate and Asset Sales represent full privatization of public-use assets, and the FHWA PPP Guidebook reports that "these contracts are perceived as not in the public interest," because the public sector relinquishes control over how the asset is maintained and priced. The Chicago Skyway and Indiana Toll Road deals are sometimes referred to as "asset sales," but this is incorrect- in reality, they were "long-term lease agreements."
The survey of state PPPs enabling legislation (prepared by Nossaman, Guthner, Knox, & Elliott, LLP for FHWA) shows that 21 states allow DBFO procurement for toll facilities.