The report underscores how states and the federal government, facing tight budget restraints and a decline in revenues, must find alternative financial resources for key transportation infrastructure projects such as maintaining and expanding the capacity of the Interstate Highway System. PPPs, while not the solution to every transportation infrastructure challenge, can be used to take on at least some of the needs provided that the federal government allows states more latitude to leverage that option, the foundation explains.

"Under the right circumstances, public/private partnerships could play a targeted role," according to the report.

A Virginia initiative adding 14 miles of High Occupancy/Toll lanes in the median of the Capital Beltway (Interstate 495) is highlighted. This work is being managed through a partnership between the Virginia Department of Transportation and a private company formed by Australia's toll-road developer Transurban and the U.S.-based Fluor Corp.

The jointly financed project is expected to be completed next year. Benefits include adding new road capacity in one of the nation's most congested regions, quicker commutes, the creation of thousands of construction and engineering jobs, and the replacement of aging infrastructure such as more than 50 bridges and overpasses.

PPPs should not be seen by policymakers as a panacea for addressing all transportation infrastructure gaps across the nation, however, the foundation states in its study. Other innovative and traditional financing solutions remain needed.

"There are too few financially viable P3 projects to meet the national need for new highway capacity and to modernize existing roads," according to the report. "No amount of enabling legislation will bring private investors into projects that are not financeable and very few highways could support themselves on tolls alone."

The six-page report, "Can Public/Private Partnerships Fill the Transportation Funding Gap?," is available at bit.ly/P3-Report.