Auckland is a car city and most residents drive. For visitors, this creates a problem: traffic can be genuinely bad on the main arterials during morning and evening rush hours, and parking in the CBD is expensive. The alternatives are improving.
The train network (AT Metro) connects Britomart in the city centre to Newmarket, Henderson, Manukau, and other suburban hubs. Trains run regularly during the day and are the best way to reach Newmarket for shopping or the North Shore via Grafton. A single HOP card covers trains, buses, and ferries — buy one at Britomart or the airport.
The ferry network is excellent for visiting Devonport and Waiheke Island, and the 12-minute crossing to Devonport is one of the nicest short trips in New Zealand. Downtown Auckland is manageable on foot — the CBD, Viaduct, and Britomart are all within 15 minutes' walk of each other, and the Domain and Auckland Museum are a 25-minute walk from the centre or a short taxi ride.