Auckland has a fairly comprehensive public transport network, including buses, trains and ferries. Buses serve most of the city every day of the year, with special NiteRider services after dark. The Link bus offers three bus loop routes in downtown Auckland which pass many of the major tourist attractions and are useful for travellers; the routes are colour-coded and buses pass frequently. The city train service is aimed primarily at commuters and is of limited use to tourists. Ferries connect to the north shore suburbs and take passengers to the Hauraki Gulf Islands. Taxis can be hailed on the street, but are more commonly booked by phone. Despite all this, many visitors find getting around Auckland frustratingly slow without a car, and for many hiring their own vehicle is still the most convenient option, especially if planning to explore beyond the city.