The Connecticut Turnpike (the part of I-95 in Connecticut) and the Merritt and Wilbur Cross Parkways. In short, Connecticut removed all tolls throughout the state.
I-30 between Dallas and Ft. Worth, toll road between 1957 and 1977. I don’t have a cite that provides the details specific to this project but, essentially, the tolls were established to pay for the project with the idea that it would be maintained as part of the interstate system.
The Turnpike Commission at the time was reluctant to turn loose of the tolls but one of the members pushed to assure the original charter was followed. A politico assuring that public trust be maintained, imagine that!
The Garden City Skyway (a massive, 2.2 kilometer long, 6 lane bridge) in Southern Ontario, Canada was opened in 1963 and the toll booths were shut down 10 years later.
Tolling was reinstated on the Evergreen Point Bridge in 2011 to help fund its replacement. No toll booths, though; it was done automatically either by transponders or license plates.
In the late 50s, they added a second bridge to Interstate Bridge across the Columbia between Portland and Vancouver to handle I-5. From 1960 to 1966 there was a toll (20 cents for cars). The new stuff was paid off and the toll ended.
Similarly, the Astoria–Megler_Bridge across the mouth of the Columbia had tolls which ended two years early!
In the NW, toll roads are despised and even bridge tolls are usually barely tolerated. So these examples “until it’s paid off” tolls are reasonably common.
There was (I recall) a 25¢ toll on the Southern State Parkway on Long Island, NY. Sometime in the 80s, the local newspaper investigated and found the bond the toll was set up to pay off was paid off years before and the toll was barely covering the cost of collecting them. The toll booth was shut down shortly thereafter. There is still a wide area on the parkway where the toll booths were.
Many years ago on a trip to Brazil I was happy to see that they had removed the tolls from the bridge that connects Rio de Janeiro with Niteroi, across Guanabara bay.
People were saying how it was great that promises were kept and that once the bridge was paid for the tolls went away.
…but they didn’t remove the toll booths, and I thought that was an ominous sign.
Sure enough, two years later when I was back I saw signs singing the praises of Onda Livre, the Brazilian equivalent of EZ Pass, and off in the distance I saw those same toll booths, brought back into service after a few years hiatus.
So when someone declares tolls gone, make sure they tear down the toll booths.
If Connecticut does restore tolls, I expect they’ll go all electronic collection, collecting tolls via EZ Pass or by reading license plates. Some of these systems don’t even require you to slow down, so it might at least avoid tying up traffic.