Also popular are Haleakala National Park, on Maui, and Hawaii Volcanoes National Park, on Hawaii, as well as numerous state parks and recreation areas. Transportation Airplanes and ships are Hawaii's chief means of transport for intrastate, interstate, and international commerce. There are public bus systems on Oahu and Hawaii islands, and the state has a few kilometers of operated railroad track. Of Hawaii's airports the busiest is Honolulu International. By the mid- 1980s, Hawaii had an installed electricity generating capacity of 1.6 million kW, and annual production was about 6.6 billion kWh.
Electricity is generated in thermal plants using imported petroleum.
These people, who had traveled across the ocean in large sailing canoes, were able to make implements and structures, and they enjoyed an excellent standard of living in Hawaii. Their economy was based on ahupuaa, land units that extended from mountaintop to the sea. Three times as much rain falls on the islands as on the adjacent sea. The islands have a wide variety of flora, including approximately 2,500 kinds of plants not found elsewhere. Common trees include koa, lehua, guava, and screw pine.