I lived on Highway 66 when it was a two lane road without any shoulders, I know about Oklahoma Highways some years ago, but I left there 35 years ago, so I am a little behind on current conditions. Expansion joints are not common in nearby states, but hey whatever.
We used to drive over into Missouri to race our cars, top speed, no bumps.
I don’t think they cut the rebar in other places.
Notice the three cuts in each wheel track on most concrete highways in Oklahoma? That is where they cut slots to put rebar in to attempt to tie the slabs together to carry the loads across from one to another. Oklahoma is one of the few states to buy into this farce. It is a repair that attempts to remedy poor construction. Each cut that is made and filled is a square cornered stress riser and potential leak path for water to enter the sub base of the road that then creates a pumped foundation failure of the pavement. It is also a money making boondoggle for someone.
Most other places probably also actually HAVE rebar in the pavement since they were inspected to meet the design specifications.
In Texas they use longer sections between expansion joints, continuous rebar and they don’t cut it when they make saw joints for expansion. The pavement usually holds up well.
You can tell when you have crossed the state line between Missouri and Oklahoma with your eyes closed. The bumps are a dead giveaway.