Shortly after work began on the Patapsco Tunnel Project on April 7, 1955, several changes were made to the plans for the approach highways. The northern terminus at US 40 was altered to allow an extension from US 40 to the southern end of the future Northeastern Expressway (now John F. Kennedy Memorial Highway). As a result, additional connections with US 40 were planned for the area around present day Exit 14. In addition, the south approach was to have a tie-in to the Glen Burnie Bypass (now I-97) then under construction. The tunnel and approach highways were completed and opened November 29, 1957 as the Baltimore Harbor Tunnel and the Harbor Tunnel Thruway, respectively. The opening of the tunnel and approach roads removed a significant amount of traffic from the streets of Baltimore and eliminated 51 traffic lights from the route of motorists passing through the city.