A rush by state and local governments to sell roads, bridges and airports to private operators for eye-popping upfront sums has all but collapsed in the recession.

That could leave taxpayers on the hook for more of the $200 billion a year needed to maintain the nation's transportation system, according to federal estimates.

An era of privately operated infrastructure seemed near when Chicago leased its 7-mile Skyway for $1.8 billion in 2003 and Indiana leased a 157-mile toll road for $3.8 billion in 2006, deals that had other governments rushing to cash in, too.

States had proposed selling all kinds of things, from highways to lotteries, to raise $10 billion or more. In return, the private companies would operate the assets during long-term leases and bank the revenue.

The purchase of government assets has all but stopped as credit has dried up. Now, with tax collections falling, state and local governments are scrambling to finance projects.

The biggest casualty so far: A $2.5 billion agreement to sell Chicago's Midway Airport fell apart in June when investors could not round up enough money.