In the Southwest United States, a group of truckers communicate over their CB radios, planning to form a large convoy in protest against the tyranny of corrupt law enforcement – specifically, the vindictive and blackmailing Sheriff Lyle "Cottonmouth" Wallace. After an altercation at a truck stop, where the truckers confront the sheriff's oppressive tactics, a popular trucker known by his handle, Rubber Duck, accidentally becomes the leader of this rebellion. As he tries to evade the sheriff's clutches, the incident snowballs into a high-speed chase, attracting more truckers and escalating beyond a simple traffic matter. The convoy becomes a symbol of freedom and resistance against authoritarian abuse, drawing national attention and growing with every mile, turning Rubber Duck into an unlikely folk hero.

Amidst the expanding chaos, Rubber Duck is joined by Melissa, a photographer looking to escape her troubled past. As they journey together, their relationship deepens, set against the background of the increasingly politicized convoy. Their travels showcase the solidarity among the truckers, as well as the diverse motivations behind each driver's decision to join the convoy. As they navigate through roadblocks and attempts at negotiation, the convoy’s purpose shifts from a personal vendetta against Sheriff Wallace to a broader fight against injustice. The moving mass of trucks becomes a moving fortress, symbolizing the collective resistance of the common people against oppressive forces.