The Boston University Bridge (originally the Cottage Farm Bridge.) and commonly referred to as the BU Bridge, is a steel truss through arch bridge with a suspended deck carrying Route 2 over the Charles River, connecting Boston to Cambridge, Massachusetts. According to the American Association of State Highway and Transportation Officials route log, the bridge also carries U.S. Route 3 across the river to its southern terminus at U.S. Route 20 (also known as Commonwealth Avenue).