You may not drive your vehicle off-road. Almost everywhere you go, Maui is paved. The only exceptions are when you travel deep into and past the town of Hana on some dirt roads, but you won’t need to go to these places unless you have family or friends who live there. Most of these roads are mild, too, unless it’s been raining. The backside of Haleakala is also forbidden, but locals still use it to drive back around the island after visiting Hana.