This short story has a dual theme and is a most interesting study of a much anticipated event during the time in which the story is set. The time period of the setting is integral to understanding the themes. Hernando's life in the jungle gives very little information from which to discern the time period, but the "swift long low convertible cars," like the Chrysler New Yorker Convertible, for instance, that flee up the highway northward set the time period around 1950. "The Highway" was published in the collection, The Illustrated Man, which was published in 1951.

After the atomic bomb was dropped on Hiroshima, the Western world was gripped by the dark fear of all-out atomic warfare. School children practiced pointless drills to "protect" themselves in the event of an atomic attack. Families dug out or built up atomic bomb shelters in their back yards or in their cellars. TV commercial public service announcements warned in chilling images about the dangers of and what to do in the event of atomic attack. The fear of atomic war was palpable--almost tangible.

It is in this time period that the story is set and this time period informs the significance of the dual themes. The first theme, which centers around those fleeing civilization, is the fear and destruction of atomic war. Bradbury gives an almost surreal glimpse into this fear of atomic war as he briefly describes the fleeing occupants of the cars as having something unidentifiable in their faces:

Five hundred, a thousand cars passed, and there was something in the faces of all of them. But they moved too swiftly for him to tell what this thing was.

The second theme, which centers around Hernando, is the contrast between civilization and the world. Ironically, Hernando's last words in the story are, "What do they mean, 'the end of the world'?" Before the last Ford of the civilized towns rushes away up the highway, the man tells him that the "atom war" had come and that it  is the end of the world.

After this final car drives away, the smell of the jungle after the rain storm that starts the story wafts up to Hernando. He picks up his plow and prods his burro to work with the familiar cry. As his life continues as always beside the now deserted highway, he wonders what will be destroyed as his "world" consisting of the river, jungle, soil, and growth and life remains unchanged.

[Recall that in the 1940s and 50s, far less was known about the global contamination and destruction of atomic radiation. Based on what is now known, the continued health and quiet life of the jungle and Hernando would be improbable.]

What is the theme of Ray Bradbury's story "The Highway"?

"The Highway" comes from a collection called The Illustrated Man, in which the narrator sees another man's tattoos move and tell each of the stories. A theme which comes up in many of the stories is technology gone awry and that a simpler life is more desirable.

In "The Highway," Hernando notes the desolate road and then is surprised to find thousands of cars racing north: to America. He learns from a car of teenagers that the atomic war is coming. They tell him this would mean the end of the world. And, here is the quote I would use, he says, "What do they mean, the world?" Hernando is a part of the "world" and yet he has not heard about this end of the world war. Is it because he is just out of the media loop; or is there also a more subtle implication about his role (a poor farmer) in the grand scheme of things.

There is a clear separation between the industrialized part of the world and the less industrialized countries; this is a separation between city and country, urban and rural, rich and poor (in this case Hernando, the farmer.) When he asks (himself) what they mean by "world," he is suggesting that the part of the world interested in war, land, and technology is different from his world. Hernando is unaware; somewhat separate from that world. If it is the end of the world, he won't know until the end, so he goes about his business. This is part of a long tradition in science fiction that, while technology has incredible benefits, the downsides can be devastating (atomic weapons).

The underlying theme is about the idea of the "world." It is as if only the more powerful, industrial countries comprise the "world" and all others are just subject to their whims and potentially, they can become collateral damage in the event of a war. Hernando either recognizes his separation from that “world” or doesn't care if the war reaches him, or, knowing he is separate from that world, he realizes there's nothing he, a poor farmer, can do.

When you hear reference to the "third world," it is a description of countries which are not necessarily less civilized (they certainly don't have world-ending weapons); these countries are just less industrialized. Hernando represents one of these ordinary people from any world: 1st, 2nd, 3rd. The term "third world" has faced criticism because it implies that it is fundamentally inferior to 1st or 2nd. And the term "third world" is based solely on industry and market; i.e., $ and power.

The overall theme is about the dangers of technology and that simpler lives are desirable and that there is still a separation between industrial and agrarian, between rich and poor. The underlying theme is about the concept of "world." In this case, the world is still separated between industrial and poorer countries. The poor, represented by Hernando and his family, can only hope the industrial countires don't screw things up for the "other" parts of the world, or the so-called "third world."