The Longfellow Bridge is a steel rib arch bridge spanning the Charles River to connect Boston's Beacon Hill neighborhood with the Kendall Square area of Cambridge, Massachusetts. The bridge carries Massachusetts Route 3, the MBTA Red Line, bicycle, and pedestrian traffic. The structure was originally known as the Cambridge Bridge, and a predecessor structure was known as the West Boston Bridge; Boston also continued to use "West Boston Bridge" officially for the new bridge. The bridge is also known to locals as the "Salt-and-Pepper Bridge" due to the shape of its central towers.