The first section of the Northern Motorway opened on 30 May 1959, in conjunction with the opening of the Auckland Harbour Bridge. The motorway totalled 7.4 km, from Northcote Road to Fanshawe Street. On its opening day, 51,000 vehicles crossed the Harbour Bridge, with southbound traffic backing up for 10 km north of the toll plaza (near the present Stafford Road exit) with vehicles wishing to cross the bridge for the first time. Initially, the Auckland Harbour Bridge Authority owned and operated the motorway between Fanshawe Street and the toll plaza, while the National Roads Board (the predecessor to the New Zealand Transport Agency) operated the remainder of the motorway from the toll plaza to Northcote Road.