As the city extends from east to west across the Tamaki Isthmus, all surface communications north and south must of necessity pass through the city. Auckland is served (from the north) by the State highway, the approach being across the harbour bridge, and also by a provincial highway which enters the city via the North-Western Motorway at Point Chevalier. The State highway continues southward as the principal outlet from the city. The Auckland Harbour Bridge, opened for traffic on 30 May 1959, carries four lanes of road traffic between Auckland city and the North Shore suburbs of Takapuna, Northcote, Birkenhead, and Milford. The bridge is carried on piers sunk in the Waitemata Harbour at depths of up to 104 ft; the steelwork itself is 3,348 ft long and has an 800–ft navigation span rising 142 ft above high-water level. The city of Takapuna, part of Greater Auckland, is 5 miles distant on the North Shore; Whangarei, 108 miles north; and Hamilton, 83 miles south. Auckland is the northern terminus of the North Island Main Trunk railway, and a secondary line continues northward to the railhead at Okaihau. A loop line, Auckland to Westfield, and a branch to the Port of Onehunga, provide additional service to areas immediately south of the city boundary.
The Port of Auckland is situated on the southern shore of the Waitemata adjoining the commercial area of the city. Because of the size of its industrial complex and its proximity to the rich farming lands of the Waikato, Auckland has become New Zealand's largest and most important port. Auckland's share of the country's total trade is 26 per cent, compared with Wellington's 21 per cent. Auckland is the chief exporter of butter (131,550 tons), milk products (142,211 tons), frozen meat (107,456 tons), hides and skins (20,365 tons), tallow (18,147 tons), and iron and steel manufactures. These products constitute 76 per cent of her total exports. For the year ended 31 December 1963 the total imports were 2,788,293 tons, coastal trade contributing 629,029 tons and overseas trade 2,111,513 tons. Exports on the other hand totalled 748,762 tons, of which 198,197 tons were coastal and 550,565 tons overseas. The principal commodities of overseas imports are: motor spirit, etc. (380,220 tons), manures (287,229 tons), iron and steel, pipes, etc. (189,078 tons), raw sugar (109,346 tons), and bulk wheat (110,952 tons). Passenger movement through the port was 45,839 persons, as well as 23,191 through passengers. The Port of Onehunga on the Manukau Harbour is also controlled by the Auckland Harbour Board. The total trade of this port amounted to 109,770 tons in 1963. The main obstacle to the progress of Onehunga as a port is the bar at the entrance to the Manukau Heads, which limits the port to coastal vessels. On the North Shore of the city is Devonport, the chief shore station of the Royal New Zealand Navy, where docking and repairs are available to naval and merchant ships alike. Overseas and internal air services operate from the RNZAF Station, Whenuapai, a joint-user airport both for civil and for military aircraft. It is located 14 miles to the north near the upper reaches of the Waitemata Harbour. Ardmore Aerodrome, 20 miles south-east, near Papakura, serves as the light-aircraft centre. An international airport, now under construction at Mangere, 13 miles south of the city, is expected to be in service by 1965.