In many countries the private sector hasbeen involved in financing infrastructure throughconcessions under a public-private partnership (PPP)program. PPP schemes, however, are somewhat underutilized intransition economies, where the potential financing gaps aresignificant and growing, and there seems to be an enormouspotential for more private sector involvement in thefinancing and operation of highway assets in thesecountries. Institutions such as the World Bank cancontribute to enhance private financing of roadinfrastructure through greater use of their guarantee power,in addition to supporting, when required, the public sectorcontribution to the construction cost of a PPP projectthrough loans. Partial risk guarantees are particularlyrelevant in the context of seeking more private involvementin the financing of road infrastructure. This paper reviewspotential applications of partial risk guarantees, therequired legal framework (for example, concession law) forattracting private capital for PPP schemes, possible stepsfor a country to launch a program of private participationin highways, the concept of greenfield and road maintenanceconcession programs, and the treatment of unsolicitedproposals. It also summarizes potential applications of theWorld Bank Toolkit for PPP in Highways as an instrument tohelp decision-makers and practitioners to define the bestPPP approach for a specific country.