Hawaii Route 31, also known as the Pi'ilani Highway, is a 38-mile road on the island of Maui in the U.S. state of Hawaii. The state road begins in at an intersection with Hawaii Routes 310 and 311 in the West Maui town of Kihei. The highway formerly ran parallel to the coast all the way to the southern terminus of the Hana Highway (Route 360), until developments in Wailea and Makena blocked access..