The untamed Piʻilani Hwy (Hwy 31) travels 25 ruggedly scenic miles between Kipahulu and ʻUlupalakua, skirting the southern flank of Haleakalā. This spectacular coastal drive starts out in lush jungle, with snaking bends through numerous gulches. Once it enters the dry side of the island, the road breaks out into magnificent, wide-open scenery, from the crashing sea to the volcano above. And hardly anyone is on it.
The road is subject to tall tales about its condition, particularly from rental-car companies. In reality it is rough and narrow in a few spots early on, with a series of unpaved sections, but easily driveable. The latter half has brand-new blacktop. There are no gas stations or other services along the way. Washouts sometimes close the road temporarily, so inquire about conditions at the Kipahulu Visitor Center.