(FORTUNE Small Business) – If there's wasabi on the menu, beware. As any highway driver knows, the true diner offers true comfort food--and aesthetic pleasure. But the land is now awash in "diners" with no real claim to history. They might serve mashed potatoes, but the pretenders are obvious even before you park your car.

A little history (with a dollop of apocrypha): Diners got their start in Providence in 1872 when Walter Scott began selling good, cheap meals from a horse-drawn cart. He later used more elaborate conveyances, setting the precedent for design in diners' 1930s heyday. Factories such as Worcester Lunch Car shipped deco-style masterpieces (no longer intended to move) with marble counters, ten or 11 stools, a view of the grill, and six to eight booths. (Tableside jukeboxes like the Rockola came later.) One classic: Savannah's Streamliner, a 1939 Worcester original now owned by the Savannah College of Art and Design, which restored it.

We can't blame diner owners for catering to new tastes. Even a purist might be seduced by the menu at the Buckhead Diner in Atlanta, for example: homemade potato chips and veal-and-mushroom meat loaf. For a state-by-state guide and news, go to www.dinercity.com or www.roadsidemagazine.com. True believers can make a pilgrimage to the American Diner Museum in Providence (www.dinermuseum.org), opening later this year.

--Jane Hodges