How common are interchanges on Hawaiis non-freeway routes?
They are rare, though not nonexistent. Oahu and Maui each have a few, such as on several segments of the Farrington Highway in southwest Oahu, and on Main Street in Wailuku on Maui. There are none on Kauai, or on the Big Island. Traffic volumes usually do not require grade separation, except for the high-speed, high-volume freeways on Oahu. Lanai and Molokai? They don’t even have stoplights! (Cool!
