I see... Strange system, I haven't heard of something similar in Europe. A lot of European toll roads have a "closed" ticket system. Others have an open system with one mainline toll barrier and perhaps a lower toll at some entrances/exits.
That system is a bit unusual, but again, it is Oklahoma we are talking about.
Before the toll plazas were moved in the early 90s to go along with the introduction of PikePass (OK's version of EZPass), the Turner & Will Rogers Turnpikes (both part of I-44) used the closed ticket system. There may have been a couple others that used this system, but I can't remember them at this point.
The old gates on the Turner Turnpike stood for several years in Oklahoma City (just east of I-35) and Tulsa (just southwest of OK 66). Too bad I wasn't yet driving age at that time, and had no clue that people took road pictures, or otherwise I would've taken pictures of them.