Many radio stations are automated. I know at least one radio station in Los Angeles that was automated in 1966. Beethoven radio is automated except M-F 8-6. The announcements are prerecorded, and the program list is probably entered in well ahead of time by a staff member. They probably don't have anyone on site better than half the time, although they may have staff members assigned to monitor the signal by listening for any problems.
There are many ways to automate a radio station. I can't say exactly how beethoven is set up, because I'm just a listener with enough knowledge to be dangerous, but I know of several possible ways to do it. I would expect they use some ideas from here, some from there, and some from somewhere else, to tune up their programming to best fit their intended audience.
--I know what I like--