A lift bridge is a type of movable bridge that raises its roadway to allow boats and ships to pass underneath. The bridge is lifted vertically using a system of cables, pulleys, and counterweights, making it an effective solution for crossing waterways where tall vessels need access. Lift bridges are commonly found in urban areas and along navigable rivers. They can be operated manually or automatically, depending on the design. Notable examples include the Chicago River bridges and the Tower Bridge in London, which showcase the engineering capabilities of lift bridge technology.