That's a practical question that doesn't have a single universal answer, as specifications can vary by municipality and manufacturer. However, based on common standards for public works and residential containers, a typical 90-100 gallon wheeled urban trash bin lid is designed to handle the weight of normal bagged waste and some incidental pressure.
Most standard polyethylene lids aren't engineered to support heavy, concentrated loads. They're primarily a cover, not a shelf. You might safely place a few lightweight bags on top, or a child might sit on it briefly, but we're talking about distributed weight of perhaps 20-30 pounds maximum before risk of cracking or hinge damage. The lid's strength comes from its curved, ribbed design which provides rigidity, but the plastic material has limits.
Exceeding this by placing heavy construction debris, attempting to stand on the lid, or stacking multiple heavy items can lead to cracks, broken hinges, or a collapsed lid. This not only damages city property but creates sanitation issues. If you regularly need to dispose of heavier materials, contacting your local waste management department for guidelines or special pickup services is the recommended approach. They can provide specifications for your specific bin model and advise on proper use.