A writer recalls a slow bus journey from New York to Mexico City and the magically restorative effect of roadside chilaquiles and eggs

At the start of summer vacation, years ago, I would catch a Greyhound bus in New York City and head back home to Mexico City. It was, for the most part, a long and nasty ride. There were endless days of sitting, not enough rest stops, and, at the soda counters where we took our meals, gummy ham sandwiches handed out by large, indifferent women. The bus usually reached the border crossing late at night. Sleepy eyed, confused and crabby, we passengers shuffled off the bus and through Mexican customs and immigration--stations of the cross that reeked of cleaning fluid--and finally onto a Mexican bus, where Mexican drivers (always two of them, always paunchy and mustachioed, always circumspect and courteous) were waiting to drive us home through the desert night.

At around six the following morning we would be wakened by the slow jolts of the bus as it pulled into the Monterrey bus station, our first stop in Mexican territory. In those days there was no terminal, only a large shed that housed a nauseating rest room, a ticket office and what might pass for a waiting room. A row of nearly identical zinc-roofed restaurants edged the parking lot.

Those of us from the capital have always chosen to see the booming industrial city of Monterrey as rather foreign, dangerously prone to northern aberrations like Protestantism, wheat-flour tortillas and punctuality. But at the restaurants in the bus station I learned to feel differently about Monterrey. Each painted metal table, invariably decorated with the logo of some local brewery, held a still life that was in itself a distillation of Mexican-ness. There was a brightly colored paper-napkin holder, a little narrow-necked bottle of Esta Salsa Sí Pica (This Sauce Really Is Hot!), an empty bottle of the same sauce acting as a toothpick holder, a small glass plate full of fragrant limes cut into quarters and a large jar of Nescafé.

As if by magic, the glum busload of passengers from the night before was transformed at the sight of these still lifes. We said good morning and thank you for the nice ride to the drivers, sat down at shared tables, introduced ourselves, rubbed our hands together happily against the clear morning's chill. From a waitress with a harsh expression and the speed of a martial artist, we ordered a plateful of fresh papaya, another of chilaquiles (a fried-tortilla dish), eggs scrambled with black beans and a large cup of steaming hot milk. There were always several of us who waited for the food to arrive with a lime quarter cupped to our face, inhaling the vivid green scent as if it could bring us new life. Then, plates in front of us, we squeezed limes over the papaya, tapped drops of Esta Salsa Sí Pica over the eggs, stirred a big tablespoon of Nescafé into the milk and considered ourselves blessed.

I can't judge whether those bus-station breakfasts were good in the culinary sense of the word; but even if they weren't, they were better than that. They were true. I would have known that this was real food, and that it belonged to a culture that was coherent, distinctive and whole, even if I had just been spirited in from Lithuania. This is the magic of road food: when you subtract atmosphere, presentation, originality, choice ingredients and refined preparation from the equation--and eliminate a restaurant's need for return business as well--what remains is either a gummy ham sandwich or the real thing.

Maybe Nescafé with hot milk is an acquired taste (although once acquired, it is heavenly), and maybe it can't really be counted as a type of cultural expression. But a spoonful of thickly soupy black beans stirred into eggs that have been beaten and dropped into a frying pan in which a little chopped onion has been allowed to frizz just around the edges (don't be stingy with the oil) is a combination that only a Mexican could have come up with. In fact, it is so essentially Mexican that every Mexican has come up with it at some point (usually when there is nothing else in the larder).

Soul-satisfying food brings people together, and highway food can be soulful anywhere. On a trip through southern Italy a few years ago, my traveling companions and I ate at a roadside stop that boasted tablecloth-covered tables, cloth napkins and waiters in black suits. There was also a blaring television that nobody watched and a small counter behind the cash register where potato chips, mints, batteries, film and cigarettes were sold. And there was a dish we couldn't get enough of. It was brought out swiftly on a huge platter: bow-tie pasta with seafood and peas in a sauce made, if I remember correctly, with cream and tomatoes. It was good, it was unlikely, it was fast, it was hearty, it was cheap, it made a group of crabby travelers friends again, and it could have existed only in Italy.

In Mexico, unfortunately, progress has not brought elegant waiters or tablecloths to roadside restaurants. Instead, it has brought a dreary institutionalization of travel. Buses have air conditioning and VCRs, making it impossible to meditate upon the passing landscape--or even know that it is there--because most passengers keep the curtains drawn over their big-screen windows, the better to enjoy Die Hard VIII on the little screen in front of them. Bus stations, with their quirks, horrors and charms, have given way to standardized terminals.

Driven by nostalgia for my early traveling days, I went to a terminal in Mexico City recently to check out the food. Of the four central terminals, I chose the one that sends passengers south to Puebla and Oaxaca. It was my fond hope that the food would reflect the traditions of these great culinary capitals, but I should have known better. At the entrance to the terminal, I found a map of the food and shopping facilities, with glyphs showing where tacos and tortas--the classic Mexican sandwiches made with French bread, refried beans, cream, jalapeño chiles and a stuffing of choice--could be purchased. The torta glyph was surrounded by three glyphs representing hot dogs.

I didn't linger over the food. I am not an expert on hot dogs, but I suspect that, by any standard, the bright pink weenies nestled in cottony bread pillows would be judged repulsive. The torta stand sold a breaded-cutlet sandwich made with processed mystery meat. The choice of taco fillings was classic--pork rinds in green sauce, potatoes and chorizo, picadillo--but unappetizing. When I saw the tray holding a filling of sliced hot dogs floating in tomato sauce--hot-dog tacos!--I decided it was time to leave.

Inside the maddeningly crowded metro station that connects to the terminal, hope revived. There was a stand selling classic Mexican sweets, where I bought a sweet, sour, delicious tamarind ball. And then I joined a few other metro travelers at a stand that sold licuados, or fresh fruit shakes. The stand was in an underground tunnel through which tens of thousands of people rush every day, but it was decorated with little jars of fresh herbs and a picture of the Virgin Mary surrounded by brightly colored lights. All the fresh fruits available for licuados were displayed in clear jars. Wooden stools were provided for the customers, so that we could take a moment to relax with our foamy drinks. I ordered a licuado of milk, bananas and walnuts, which was spun in a blender on order, and when I had finished my first glassful, the friendly man behind the counter gave me a refill, gratis. This was road food too, of the best kind, and it could have existed nowhere else but in Mexico. Modern Mexico.

Alma Guillermoprieto writes about Latin America for The New Yorker and The New York Review of Books. She is the author of Samba and The Heart that Bleeds (both published by Vintage Books).