In the UK there is the concept of a "service station" which is a gas station, a restaurant, a bunch of shops, in an organised blob of shops and parking etc. en.wikipedia.org/wiki/Motorwa... For some reason the US doesn't really have that except informally when Starbucks opens next to a gas station.
Bizarrely good tour of a standard UK service station, which is also a parody of a late-70s sci-fi series: www.youtube.com/watch?v=9Euk...
The US equivalent would be a "truck stop," I'd think? They tend to cater more to long-haul truckers than passenger vehicles. Spaced farther out, though, and fewer regulations on them than the UK has for motorway services. en.wikipedia.org/wiki/Truck_s...
some roads do have service stations. like the turnpike in Florida has one every so many miles, and are exactly as you described. I remember stopping at one as a kid and getting a wax dinosaur figure from a vending machine, that was hot as hell when it came out. (it made them in the machine)
You aren't rural enough. Buc-ee's is seriously amazing in the more rural states. It's like a Super Store inside buc-ees.com/about/
I stopped at one on the way home from Texas and it was incredible. Clean bathrooms, good hot food, limitless options. Wish we had them up here in Illinois.
Ontario Canada has ONRoute stops along the major highways. Essential. en.wikipedia.org/wiki/ONroute