Although many travelers opt to rent cars during their stay in Oslo, but this is not really needed for most people.  The public transportation system, ( http://www.tripadvisor.com/Travel-g19... ) is one of the most extensive public transportation systems worldwide for a city as small as Oslo.  The public transportation system, including the busses, trams and metro system which traverse the city and reach the outlying areas of Oslo, are all streamlined by the city government. In addition, the national railway operates a number of local/commuter trains to suburbs and neighboring towns. City transport and railway have a number of joint stations (hubs) notably Oslo Central Station/Jernbanetorget (Oslo S) and Nationaltheateret. This means that transportation is efficient and easy for visitors to understand, as there is only one ticketing system to learn for travel on any of the public transportation lines. All sights are available by public transport.

Metro

Tickets for the public transportation system are sold at vending machines around the city, as well as at the main stations in the city center and in some shops close to the T-bane system (Narvesen).  Visitors should keep an eye out for the free public transportation map which is available around the city and can be picked up at tourist information centers and post offices.

Visitors should also be aware of the ferry system which runs to Bygdoy peninsula where a majority of the museums frequented by tourists are located.  The ferry system is actually also run by the same governing agency as the other public transportation in Oslo. They also run ferries for the islands in the Inner Oslofjord.

Taxis are another option in Oslo.   More information is available at http://www.tripadvisor.com/Travel-g19... .  Taxis are relatively expensive for visitors.