Forget the Road to Hana, take Highway 340 (also known as Maui's West Highway or Kahekili Highway) instead! The drive itself can be done in a couple of hours without stops. In order to really appreciate the views, however, it will take you between four and five hours. Take your time, explore, eat lunch, enjoy some banana bread, take home some preserves and soak in the views and the people you meet along the way.
Halona cove, Oahu. Beautiful beach right next to the halona blowhole on the southeastern shore. Be careful though...in this area is one of the most dangerous ocean currents in the world, Ka Iwi, otherwise known as the Moloka'i Express. Source: Kanu Hawaii