What type of bridge typically features simple spans of 75 feet or more?

The steel box-girder bridge design is particularly well-suited for spans of 75 feet or more due to its structural efficiency and strength. The box-girder’s hollow section allows for a high strength-to-weight ratio, making it capable of safely spanning considerable distances while maintaining stability and rigidity. This design minimizes the amount of material required compared to other types, allowing for longer spans without compromising the integrity of the structure.

Steel box-girders also have the advantage of being able to handle greater loads and resist lateral forces due to their closed shape, which provides excellent torsional resistance. This characteristic makes them an optimal choice for applications where long spans are essential, such as highway overpasses or large commercial infrastructures.

While other bridge types may handle varying spans effectively, the particular strengths of steel box-girders position them ideally for spans of 75 feet or more, enabling them to meet the durability and safety standards required for modern engineering challenges.