Roger Ebert gave the film three out of four stars and wrote, "What I liked about Two-Lane Blacktop was the sense of life that occasionally sneaked through, particularly in the character of G.T.O. (Warren Oates). He is the only character who is fully occupied with being himself (rather than the instrument of a metaphor), and so we get the sense we've met somebody".

In his review for The New York Times, Vincent Canby wrote, "Two-Lane Blacktop is a far from perfect film (those metaphors keep blocking the road), but it has been directed, acted, photographed and scored (underscored, happily) with the restraint and control of an aware, mature filmmaker".

Time magazine's Jay Cocks wrote, "The film is immaculately crafted, funny and quite beautiful, resonant with a lingering mood of loss and loneliness ... Not a single frame in the film is wasted. Even the small touches — the languid tension while refueling at a back-country gas station or the piercing sound of an ignition buzzer — have their own intricate worth".

In his review for the Village Voice, J. Hoberman wrote, "Two-Lane Blacktop is a movie of achingly eloquent landscapes and absurdly inert characters". In his review for the Chicago Reader, Jonathan Rosenbaum wrote, "The movie starts off as a narrative, but gradually grows into something much more abstract — it's unsettling, but also beautiful".