I thought he took quite a long time to do the run-in to the ferry, but that may have been a mistaken impression.
I can't find the 'regular schedule' on their F******* page, only this:
The Cave-In-Rock Ferry operates 6:00 a.m., to 9:50 p.m., CT, daily. The last run from Illinois is at 9:40 p.m. The last run from Kentucky is at 9:50 pm.
That may be as close to a schedule as it gets.
The hours were reduced from 16 a day to 12 last year:
As the state transportation departments have intervened, there have probably been more changes.