There are only 30 mi of paved road on the island. Keomuku Highway starts just past the Lodge at Koele and runs north to Shipwreck Beach. Manele Road (Highway 440) runs south down to Manele Bay and Hulopoe Beach. Kaumalapau Highway (also Highway 440) heads west to Kaumalapau Harbor. The rest of your driving takes place on bumpy, muddy, secondary roads, which generally aren't marked.
You'll never find yourself in a traffic jam, but it's easy to get lost on the unmarked dirt roads. Before heading out, ask for a map at your hotel desk. Always remember mauka (toward the mountain) and makai (toward the ocean) for basic directions. If you're traveling on dirt roads, take water. People still drive slowly, wave, and pull over to give each other lots of room. The only gas station on the island is in Lanai City, at Lanai City Service (open 7 to 7 daily).
Renting a four-wheel-drive vehicle is expensive but almost essential if you'd like to explore beyond the resorts and Lanai City. Make reservations far in advance of your trip, because Lanai's fleet of vehicles is limited. Lanai City Service, a subsidiary of Dollar Rent A Car, is open daily 7 to 7. Jeep Wranglers and minivans go for $139 a day, full-size cars are $80, and compact cars are about $60. Sometimes a better deal (with fewer restrictions on where you can drive) can be found by booking through B&B owners.
Lanai City Service (Lanai Ave. at 11th St. 808/565-7227 or 800/533-7808).