The Michigan Avenue Bridge (officially DuSable Bridge) is a bascule bridge that carries Michigan Avenue across the main stem of the Chicago River in downtown Chicago, Illinois, United States. The bridge was proposed in the early 20th century as part of a plan to link Chicago's south side and north side parks with a grand boulevard. Construction of the bridge started in 1918, it opened to traffic in 1920, and decorative work was completed in 1928. The bridge provides passage for vehicles and pedestrians on two levels; it is an example of a fixed trunnion bascule bridge, which is also known as a "Chicago style bascule bridge".