Abstract: A system for providing ballast for cargo bed of trucks consisting of a multiplicity of interlocking low-profile hollow containers interconnectively-assembled across the entirety of a cargo bed of a pickup truck and secured to the bed of the truck with bolts. When the individual containers are filled with a weighted material, such as water or sand, each container preferably will weight less than 50 pounds, and the flat weighted structure provides additional traction to the drive wheels of the truck on slippery road surfaces. In an alternate application, the filled containers are stacked at selective locations and secured to the truck bed to provide a counter-balancing weight for a heavy piece of cargo that is not placed in the gravitational center of the cargo bed.