Kansas has center plazas on their turnpikes. I like the idea of those. That way you can turn around or meet someone halfway. Many times I have done just that for a part.Coming from out of state and having never seen anything like it before I thought the idea of having plazas in the middle of the turnpikes a great and novel idea. As for the gas stations I would say Oklahoma has the upper hand over most.
Since my retirement, I have had no use for the turnpike between Tulsa and the city. I was very surprised to see it had been bulldozed and a new one popped up further east toward Tulsa.