Is there a Spanish equivalent of the Ciao/AutoGrill chain that you see in Italy? We may have a day or two when we are on a major road during the lunch hour and would like something good but quick and relatively inexpensive to eat. Ciao/AutoGrill fit the bill in Italy. Thank you.
Those things exist along the freeways just as they do in France and Italy. I can't remember the names of any of the chains, but they'll show up for what they are.
Our habit is to have a sack of bread, cheese, sausage, fruit, etc. in the car and dive into it in the parking lots or picnic tables at the service area. It's much easier or the belly.
Rather than chain food, I'd keep my eyes peeled for a "Venta" somewhere along the road (usually right before a cloverleaf (or whatever those big direction changing structures are called.) The Venta will be a Mom and Pop establishment which focuses on home cooking style food, mostly for truckers. Another option would be to have lunchtime coincide with an industrial park (Poligono Industrial or Pol. Ind. on most signs) just outside of any city or large town. Once in the poligono, just cruse the streets for a few minutes and look for the place with the largest collection of semi trailers in the parking lot.
I second Adynata's advice. We had some great meals, local cuisine, simple and inexpensive, at places with lots of trucks in the parking lot.