In 2002, there were an estimated 1,360 km (845 mi) of roads in the Solomons, of which only 34 km (21 mi) were paved. Of the 1,326 km (824 mi) of unpaved roads, about 800 km (497 mi) belong to private plantations. Shipping services link the Solomons with other Pacific islands, Australia, Japan, and Europe. Honiara is the principal port, followed by Ringi Cove. A fleet of government vessels provides interisland connections and handles about one-third of total tonnage carried. There were 31 airports in 2001, only 2 of which had paved runways. Henderson's Field, on the northern coast of Guadalcanal, is the site of Honiara's civil airport. Solomon Airlines provides regular flights between islands and to nearby Papua New Guinea and Vanuatu. In 1997, Solomon Airlines carried 94,000 passengers on domestic and international flights.