As of 2002, there were 240 km (149 mi) of roadways on the major islands, of which 42 km (26 mi) are paved. Over 90% of all vehicles are located on the main islands of Pohnpei, Moen (in Truk), Kosrae, and Yap. The state of Yap provides public bus transportation, primarily used by students. International shipping services are provided by 8 companies, some of them Japanese. There are commercial harbor facilities at Kolonia, Moen, Okat, and Colonia. The Federated States of Micronesia have no merchant marine, but inter-island shipping service is provided by 6 government-owned vessels. In 2001, there were 7 airports, 6 of which had paved runways. International and interstate scheduled airline services are provided by Continental/Air Micronesia, Air Nauru, and Pacific Missionary Aviation.