“Budget gaps are starting to increase the viability of public-private partnerships,” said Norman Y. Mineta, a former secretary of transportation who was recently hired by Credit Suisse as a senior adviser to such deals.

This fall, Midway Airport of Chicago could become the first to pass into the hands of private investors. Just outside the nation’s capital, a $1.9 billion public-private partnership will finance new high-occupancy toll lanes around Washington. This week, Florida gave the green light to six groups that included JPMorgan, Lehman Brothers and the Carlyle Group to bid for a 50- to 75 -year lease on Alligator Alley, a toll road known for sightings of sleeping alligators that stretches 78 miles down I-75 in South Florida.

Until recently, the use of private funds to build and manage large-scale American infrastructure assets was slow to take root. States and towns could raise taxes and user fees or turn to the municipal bond market.

Americans have also been wary of foreign investors, who were among the first to this market, taking over their prized roads and bridges. When Macquarie of Australia and Cintra of Spain, two foreign funds with large portfolios of international investments, snapped up leases to the Chicago Skyway and the Indiana Toll Road, “people said ‘hold it, we don’t want our infrastructure owned by foreigners,’ ” Mr. Mineta said.

Image Two foreign funds with large portfolios of international investments have gained control of the Chicago Skyway. Credit... Peter Wynn Thompson for The New York Times

And then there is the odd romance between Americans and their roads: they do not want anyone other than the government owning them. The specter of investors reaping huge fees by financing assets like the Pennsylvania Turnpike also touches a raw nerve among taxpayers, who already feel they are paying top dollar for the government to maintain roads and bridges.