Palau International Airport provides scheduled direct flights to Guam and Manila. In addition, the states of Angaur and Peleliu have regularly served international airports. Freight, military and holiday cruise ships often call at Malakal Harbor, on Malakal Island outside Koror. The country has no railways, and almost half of the roads are unpaved (of the 61 km/38 mi of highways, only 36 km/22 mi are paved). Driving is on the right and the speed limit is 40 km/h (25 mph). Taxis are available in Koror. They are not metered and fares are negotiable. Only Koror maintains a bus service. Transportation between islands mostly relies on private boats and domestic air services.