This Central Oahu corridor is flanked on the east by the Koolau Mountain Range, which runs the full length of the windward coast from Hawaii Kai and Makapuu on the southeast to Kahuku on the northeast point.
To the west of the central corridor is the Waianae Mountain Range, stretching from the Waipahu-Makakilo area through Nanakuli, Waianae, and Makaha to Kaena Point on the remote northwest tip of the island.
Oahu has a limited freeway system that is heavily used and always busy. The H-1 Freeway connects the Kahala area behind Diamond Head with Waikiki, downtown Honolulu, the airport, Pearl Harbor and extends west out to Waipahu and the Kapolei near Barber’s Point Naval Air Station.
The H-2 Freeway links the central corridor of Pearl City and Wahiawa area. And the new H-3 Freeway links Kaneohe and Kailua on the windward coast with the Halawa and Pearl Harbor areas on the leeward coast via a spectacular route up and over (through tunnels) the Koolau Mountains. This new route provides some spectacular views of forest, valleys and mountains.
Two other trans-Koolau routes link the windward coast with the leeward coast. These are the Pali Highway 61 and the Likelike Highway 63. Both routes connect downtown Honolulu with the Kaneohe and Kailua areas.