As a result, the OTA could not obtain financing to build that proposed turnpike and turned the initial plans including surveys and blueprints over to the Oklahoma Department of Transportation in 1956 for the construction of I-35 as a freeway on that same alignment, which was completed in several stages between 1958 and 1962.

Also proposed but never built was a toll road roughly following what would later become I-35 between Oklahoma City and the Red River north of Gainesville, Texas that included a spur route veering from the main route north of Ardmore veering northeastward past Ada to tie in with the Turner Turnpike near Stroud, Oklahoma.

Also proposed in the 1990s, but never built was an extension of the Muskogee Turnpike from its current southeastern terminus at I-40 southeastward toward Poteau.

[3] Most customers pay an initial $40 in prepaid tolls, which they can refill at their own convenience or have funds automatically withdrawn to replenish the account if it falls below a threshold.

[4] Oklahoma turnpikes also accept all transponders from Kansas (K-TAG) and Texas (EZ TAG, TollTag, TxTag), and SunPass from Florida, and ExpressToll from Colorado.

On July 25, 2021, toll collection booths on the Kilpatrick Turnpike were closed and replaced with the new cashless pay-by-mail system known as PlatePay.