Abstract: A thermoformed thermoplastic truck bedliner has a bottom wall with parallel front-to-back ribs which overlies the floor of a truck cargo bed. Two side walls extend upwardly on opposite sides of the bottom wall and are joined at a front wall. Ribs of a normal height define the load support surface of the bedliner bottom wall, while regions of parallel ribs which are lower in height than the normal ribs define cargo containment regions. The intersection of the reduced height ribs with the normal height ribs defines ridges which restrain escape of cargo in the front-to-back direction, while the bedliner side walls and elevated height protrusions on normal height ribs adjacent to the cargo containment regions restrain side-to-side displacement of the cargo.