Steel bridges are structures made primarily from steel, designed to span physical obstacles like rivers or roads. They are known for their strength, durability, and ability to support heavy loads, making them ideal for both vehicular and pedestrian traffic. Steel's resistance to weather and corrosion also contributes to the longevity of these bridges. There are various types of steel bridges, including beam bridges, truss bridges, and arch bridges. Each design serves different purposes and can be chosen based on factors like the distance to be crossed and the environment. Overall, steel bridges play a crucial role in modern infrastructure.