A number of big toll roads have been privatized for 75 or 99 year terms, with private companies setting and collecting tolls and responsible for the maintenance.
Road use taxes and gas taxes were not lowered though, despite the transfer of responsibility to private hands.
“In 2006, Mayor Daley leased out the Chicago Skyway for 99 years for $1.8 billion.”
‘On June 29, 2006, in what may serve as a “test case” for the privatization of other major highways in the United States, the state of Indiana received $3.8 billion from a foreign consortium made up of the Spanish construction firm Cintra and the Australian Macquarie Infrastructure Group, and in exchange the state ceded operation of the 157-mile (253 km) Indiana Toll Road for the next 75 years to these outside corporations. The consortium will collect all the tolls.”
https://en.wikipedia.org/wiki/Private_highways_in_the_United_States
those examples are NOT privatized,