Within the memory of those yet living, these rooms had a purpose:

That’s at the fancy Chautauqua Lake rest area on eastbound I-86.
The majority of NY Interstate rest areas are, suffice it to say, far less ornate. Their walls now sport bare phone mounting plates and cut-off cables.
They don’t have any phone books these days, either…
Also gone from the scene: phone booths. If Clark Kent needs a place to change into his Superman costume where will he go? A stall in a smelly public bathroom? The Man Of Steel should never suffer such an indignity!
Those would be at the other rest areas along I-86… [sigh]
Waiting for a guest to arrive on the shamefully late Amtrak (8AM schedule, 3PM arrival) in 2005, I discovered the shortage of pay phones, and got my first cell phone. As I recall, the first(?) Superman movie had a nice sight gag on Clark Kent’s reaction to phone kiosks.
The FCC claims that there were 2.1 million pay phones in the US in 1999, at their peak, and 152,000 in the US in 2014. http://transition.fcc.gov/wcb/iatd/other.html
Somewhere in my collection of curious historical cruft, I have a copy of Wellington’s (NZ) 1st phone directory (circa 1900 I think), a single sided A5 size sheet – no numbers, just a list of subscriber names. When I was a kid in the 1960’s, our phone number was ‘2’. Dad was the local doctor. The policeman’s number was ‘1’. The exchange was voice operated and if you couldn’t reach the person you were calling, you might sometimes get friendly advice that “Oh, I think they are round at the Smith’s place, do you want me to try there instead?” :-)
And not by a “I didn’t get that” robot, either: the operators knew you by voice!
My folks ran a home restaurant with a pay phone on the wall and I still hate making phone calls…