Route 107 begins in Revere at an interchange with Route 16 just north of the Chelsea town line. The route serves as Broadway, the main street through the city of Revere. The route intersects Route 60 at Brown Circle. From the rotary, the route continues through the Rumney Marsh Reservation as the Salem Turnpike, entering Saugus over the Pines River. The route continues through the marsh with little development along the straight, flat section of roadway. The road enters Lynn via the Belden Bly Bridge over the Saugus River. In Lynn, Route 107 becomes Western Avenue, immediately passing the General Electric River Works. The route continues through the city, passing the western end of Lynn Commons before intersecting Route 129. The route passes Bayridge Hospital and Fraser Field before meeting Route 129A, running concurrently for approximately half a mile eastward until Route 129A turns southward. The concurrency with Route 129A was the original alignment of Route 129 prior to the creation of Route 129A in 1996. The route crosses Floating Bridge Pond, so named because the original roadway was an actual floating bridge, before entering the city of Salem. Route 107 in Salem travels as Highland Avenue, heading uphill and passing the area of the North ShoreChildren's Hospital before the road meets Boston Street at Essex Street. Route 107 turns west along Boston Street before turning northward again along Bridge Street, not far from Gallows Hill Park, site of the hanging during the Salem witch trials. The route travels along the North River before crossing under Route 114 with ramp access to that route. The route then passes the Salem MBTA station before meeting the new Bridge Street Bypass. Completed in 2008, Route 107 now follows the new bypass, keeping traffic from the MBTA station off of the busy Bridge Street, following just west of the MBTA commuter tracks before ending at Route 1A at the Salem end of the Veterans Memorial Bridge over the Danvers River. Prior to the completion of the Bridge Street Bypass, Route 107's northern end was at the intersection of Bridge Street and Winter Street, north of Salem Commons, where Route 1A turns from Winter Street to Bridge Street northbound. Because of the moving of the northern end, the route was lengthened from to.