The mountainous nature of New Zealand has made the development of rail and road communications difficult and expensive, particularly on the South Island. In 2002, 3,908 km (2,428 mi) of state-owned railways were operative. New Zealand has electrified some 506 km (314 mi) of its rail lines in order to reduce dependence on imported fuel.
Capital investment in roads exceeds that for all other forms of transport service. Total length of maintained roadways as of 2002 was 92,200 km (52,293 mi), of which 53,568 km (33,287 mi) were paved, including 144 km (89 mi) of expressways. As of 2000, registered motor vehicles included 1,719,077 passenger cars and 479,281 commercial vehicles. The 1,609 km (999 mi) of waterways are of little importance in satisfying total transportation requirements.
With a registered merchant marine of only eight ships, totaling 68,427 gross tons in 2002, New Zealand is largely dependent on the shipping of other nations for its overseas trade. In 1974, a government-owned firm, the Shipping Corp. of New Zealand, was set up to operate shipping services; its trade name, the New Zealand Line, was adopted in 1985. Auckland and Wellington, the two main ports, have good natural harbors with deepwater facilities and modern port equipment. Other ports capable of efficiently handling overseas shipping are Whangarei, Tauranga, Lyttelton (serving Christchurch), Bluff, Napier, Nelson, Dunedin, and Timaru.
New Zealand had 106 airports in 2001, 46 with paved runways. Thirteen are major air facilities, of which those at Auckland, Christchurch, and Wellington are international airports. The government-owned Air New Zealand Ltd. operates air services throughout the Pacific region to Australia, Singapore, Hong Kong, Tokyo, Honolulu, and Los Angeles, among other destinations. In 2001, 11,094,800 passengers were carried on scheduled domestic and international flights.