Paved roads circle Hiiumaa and cover several side routes; the rest are unsealed. Like many of the quiet nooks of rural Estonia, Hiiumaa is a good place to explore by bike. It's relatively flat and none of its roads are particularly busy – unless you happen to hit a queue of traffic coming off the ferry.
There are petrol stations at Kärdla and Käina. Many accommodation providers can arrange car or bike hire, as can Jaanus Jesmin in Kärdla, which rents out cars from €20 per day.
Buses, nearly all radiating from Kärdla but some from Käina, get to most places on the island, though not very often. Schedules are posted inside the bus station in Kärdla and online at www.peatus.ee.