The book received a mixed reaction from the media in 1957. Some of the earlier reviews spoke highly of the book, but the backlash to these was swift and strong. Although this was discouraging to Kerouac, he still received great recognition and notoriety from the work. Since its publication, critical attention has focused on issues of both the context and the style, addressing the actions of the characters as well as the nature of Kerouac's prose.
In his review for The New York Times, Gilbert Millstein wrote, "its publication is a historic occasion in so far as the exposure of an authentic work of art is of any great moment in an age in which the attention is fragmented and the sensibilities are blunted by the superlatives of fashion" and praised it as "a major novel." Millstein was already sympathetic toward the Beat Generation and his promotion of the book in the Times did wonders for its recognition and acclaim. Not only did he like the themes, but also the style, which would come to be just as hotly contested in the reviews that followed. "There are sections of On the Road in which the writing is of a beauty almost breathtaking...there is some writing on jazz that has never been equaled in American fiction, either for insight, style, or technical virtuosity." Kerouac and Joyce Johnson, a younger writer he was living with, read the review shortly after midnight at a newsstand at 69th Street and Broadway, near Joyce's apartment in the Upper West Side. They took their copy of the newspaper to a neighborhood bar and read the review over and over. "Jack kept shaking his head," Joyce remembered later in her memoir Minor Characters, "as if he couldn’t figure out why he wasn’t happier than he was." Finally, they returned to her apartment to go to sleep. As Joyce recalled: "Jack lay down obscure for the last time in his life. The ringing phone woke him the next morning, and he was famous.”
The backlash began just a few days later in the same publication. David Dempsey published a review that contradicted most of what Millstein had promoted in the book. "As a portrait of a disjointed segment of society acting out of its own neurotic necessity, "On the Road", is a stunning achievement. But it is a road, as far as the characters are concerned, that leads to nowhere." While he did not discount the stylistic nature of the text (saying that it was written "with great relish"), he dismissed the content as a "passionate lark" rather than a novel."
Other reviewers were also less than impressed. Phoebe Lou Adams in Atlantic Monthly wrote that it "disappoints because it constantly promises a revelation or a conclusion of real importance and general applicability, and cannot deliver any such conclusion because Dean is more convincing as an eccentric than as a representative of any segment of humanity." While she liked the writing and found a good theme, her concern was repetition. "Everything Mr. Kerouac has to say about Dean has been told in the first third of the book, and what comes later is a series of variations on the same theme."
The review from Time exhibited a similar sentiment. "The post-World War II generation—beat or beatific—has not found symbolic spokesmen with anywhere near the talents of Fitzgerald, Hemingway, or Nathanael West. In this novel, talented Author Kerouac, 35, does not join that literary league, either, but at least suggests that his generation is not silent. With his barbaric yawp of a book, Kerouac commands attention as a kind of literary James Dean." It considers the book partly a travel book and partly a collection of journal jottings. While Kerouac sees his characters as "mad to live...desirous of everything at the same time," the reviewer likens them to cases of "psychosis that is a variety of Ganser Syndrome" who "aren't really mad—they only seem to be."
On the Road has been the object of critical study since its publication. David Brooks of The New York Times compiled several opinions and summarized them in an Op-Ed from October 2, 2007. Where as Millstein saw it as a story in which the heroes took pleasure in everything, George Mouratidis, an editor of a new edition, claimed "above all else, the story is about loss." "It's a book about death and the search for something meaningful to hold on to—the famous search for 'IT,' a truth larger than the self, which, of course, is never found," wrote Meghan O'Rourke in Slate. "Kerouac was this deep, lonely, melancholy man," Hilary Holladay of the University of Massachusetts Lowell told The Philadelphia Inquirer. "And if you read the book closely, you see that sense of loss and sorrow swelling on every page." "In truth, 'On the Road' is a book of broken dreams and failed plans," wrote Ted Gioia in The Weekly Standard.
John Leland, author of Why Kerouac Matters: The Lessons of On the Road (They're Not What You Think), says "We're no longer shocked by the sex and drugs. The slang is passé and at times corny. Some of the racial sentimentality is appalling" but adds "the tale of passionate friendship and the search for revelation are timeless. These are as elusive and precious in our time as in Sal's, and will be when our grandchildren celebrate the book's hundredth anniversary."
To Brooks, this characterization seems limited. "Reading through the anniversary commemorations, you feel the gravitational pull of the great Boomer Narcissus. All cultural artifacts have to be interpreted through whatever experiences the Baby Boomer generation is going through at that moment. So a book formerly known for its youthful exuberance now becomes a gloomy middle-aged disillusion." He laments how the book's spirit seems to have been tamed by the professionalism of America today and how it has only survived in parts. The more reckless and youthful parts of the text that gave it its energy are the parts that have "run afoul of the new gentility, the rules laid down by the health experts, childcare experts, guidance counselors, safety advisers, admissions officers, virtuecrats and employers to regulate the lives of the young." He claims that the "ethos" of the book has been lost.
Mary Pannicia Carden feels that traveling was a way for the characters to assert their independence: they "attempt to replace the model of manhood dominant in capitalist America with a model rooted in foundational American ideals of conquest and self-discovery." "Reassigning disempowering elements of patriarchy to female keeping, they attempt to substitute male brotherhood for the nuclear family and to replace the ladder of success with the freedom of the road as primary measures of male identity."
Kerouac's writing style has attracted the attention of critics. On the Road has been considered by Tim Hunt to be a transitional phase between the traditional narrative structure of The Town and the City (1951) and the "wild form" of his later books like Visions of Cody (1972). Kerouac's own explanation of his style in "Essentials of Spontaneous Prose" (1953) is that his writing is like the Impressionist painters who sought to create art through direct observation. Matt Theado feels he endeavoured to present a raw version of truth which did not lend itself to the traditional process of revision and rewriting but rather the emotionally charged practice of the spontaneity he pursued. Theado argues that the personal nature of the text helps foster a direct link between Kerouac and the reader; that his casual diction and very relaxed syntax was an intentional attempt to depict events as they happened and to convey all of the energy and emotion of the experiences.