Rest stops in Texas are maintained by the state highway department and are basically pit stops. Some have little more than a trash can, while others have restrooms, picnic tables, barbecue grills and maybe vending machines.
And neither of the two I mentioned above have the eastbound and westbouund sections connected, so there’s no savings in facilities.
Jason-
Rest stops rarely have gas stations and restaurants. (Primarily because, as has been stated, this is a violation of the Interstate Highway charter …) They are, as you suggest, primarily in the middle of nowhere. There are typically some bathrooms, maybe some vending machines and picnic tables if you’re lucky. It’s just a place to stop and, you know, rest, in the middle of a long road trip. Many rest stops on major cross-country routes have large parking areas for semis. It’s far cheaper and more efficient for long-haul truckers to stop for the night & sleep in the back of their cab than to get a motel room.
We’re confusing a couple uses of the term. In the East, you have toll roads, like the NY Thruway where you have to get a ticket when you get on, and pay when you get off. It becomes a “closed system” - if you exited to go into a town for gas, you would have to pay extra to get back on again. You have stops on these things that have restaurants and gas stations so you don’t have to exit. There are also various schemes for how the businesses are licensed and managed, which nobody is ever happy with. At one time, a single company got a contract to provide the service stops on the NY Thruway. I don’t know if that’s still the case.
Personally, I don’t associate those things with the term “rest stop”, but they are clearly what some people have been talking about.
The other use of “rest stop” is an area with parking, restrooms, picnic tables, etc. Plenty of which exist on CA interstates.
To Jason:
Hon, I work for CalTrans, and I can tell you: we definitely have rest stops here. For a while many were closed, because they were havens for “illicit activity.” From drug dealing in the rest rooms to hookers setting up shop to service the truckers, a bit more than “resting” was going on.
If you look, you’ll find a few.
~VOW
Apparently, the NY Thruway system is now calling them “Travel Plazas”, and they have a small group of regular gas stations and fast food joints in each one:
In some Western US states, I forget just which ones, there are large rest stops on one side of the the highway. Traffic in one direction can exit to their right, but traffic from the other direction requires an over- or under-pass to share the same facility. This is slightly better than a shared median system where both sides would have to exit left or use an overpass.
Traffic corridors have to be carefully designed to avoid letting you get back on the wrong side of the highway!
They got one like that in Kansas heading into Manhattan from the east. Man that stop is nice! Pearched among all these evergreens. It was almost like a little town.
The Florida Turnpike has Rest Stops in the middle. But these are not only Rest Stops (as compared to those on other FL Highways) but also have Gas, Fast Food, Travel Info (Disney, etc.), etc. etc.
I think they did this to save and make more money because people prefer to fill up gas or go to the restaurant on the turnpike rather than pay toll, go out of the turnpike, pay toll and get back on.
However, the rest stops are notoriously far apart, so if you are low on gas and driving a gas guzzler, you have to be careful.
OH AND I HATE ORLANDO COS ITS FULL OF TOLL ROADS 
Thanks Yabob and VOW, it makes sense now. I guess my mental image of what people were describing just didn’t mesh with reality.
Here In New Hampshire we even have state-run liquor stores in some rest stops. 
Oh yeah! One of the first signs you see on Route One when you enter the Granite State is:
GUNS
FIREWORKS
LIQUOR
sayeth this former MA resident. It’s a hoot.
That said, I’ve never felt particularly unsafe up there, and the people are pretty nice. But it is funny to think you’ve passed into some sort of libertarian/anarchist paradise from careful, nannyish Massachusetts.
And the big-ass state liquor store is on–93? It’s fun to see too, although for really finding out what makes a state itself there’s no beating driving on the roads that USED to be the main drag.
Just as a final thought on the OP:
I was defending the practicality of existing “rest stops in the median,” almost all of which are on turnpikes and the like. Rest stops on turnpikes include restaurants and giftshops, so putting them in the median or building an over/underpass does save a significant amount of money. Also it allows easier access for the staff of these facilities. These turnpikes don’t have parallel roads, so the expansion dealie is a non-issue.
Placement of rest stops on regular freeways is indeed rather arbitrary.
There’s a McDonald’s in the median of the Chicago Skyway toll plaza. Wish I could find a photo of it on line – it truly has to be seen to be appreciated.
I don’t think there is even a reason to build rest stops anymore now that there is a Wal-mart in every town over 3,000. Why stop at a hot smelly cinderblock outhouse like building with a few picnic tables and a vending machine when you can stop at Wallyworld and get your eyes examined, get a haircut, get a family portrait done, develop your photos, get your oil changed, eat a Big Mac, and pick up a couple of fishing lures (I think they might even have bathrooms). I haven’t stopped at a rest stop in years- they just seem dangerous to me- the traffic, the isolation, etc.
In MD, Chesapeake House and Maryland House on 95 from Baltimore to DE fit the question nicely. Gas, fast food, and convienence items are sold there. They are in the median zones. They get a lot —perhaps at times too much— business and are rather high priced.
They are in great contrast to the side-of-the-road stops in CA, which are as chriscya describes them: “hot, smelly cinderblock outhouse-like building with a picnic table and vending machine”.
However, not being a fan of Wal-Mart, I would extend chriscya’s description to some of them as well, adding noise, chaos, and long lines for shoddy merchandise.
Mehitable: Is a picture of that sign posted anywhere on the web?
And, right up I-95, Delaware has the same arrangement.
I might also note that the Belt Parkway in Brooklyn, NY, has a single gas station in the middle of 6 lanes of usually crowded traffic. I’m not sure why anyone stops there, considering the price of gas there is usually about 20 to 30 cents a gallon higher than other stations.
IIRC, there a few of these on I-95 up past Baltimore and ini DE. I was surprised when I first saw them, as we don’t have them down here in VA. They may have been on the NJ Turnpike, but I don’t recall at the moment.
I obviously need to clean my glasses.
On the NY Thruway it used to be that it didn’t cost any more for a point-to-point trip if you got off and back on at the same intermediate exit, and there was at least one exit where you could save 5 cents by doing so.
I believe the MA Turnpike was the same (no extra cost) although since I got an electronic Fast-Lane pass and I don’t watch as closely, and they’ve changed the rates anyhow, I’m not sure if its still so.