By Metro
Oslo has one of the largest metro systems in Europe. It is known as the Tunnelbane or mainly just T-bane in Norwegian.
To find a T-bane station, just look for the blue and white logo with a "T" within a circle. There are six lines, but the network is easy enough to figure out: all lines merge together to one single tunnel through the city center, from Majorstuen through Jernbanetorget Oslo S/Oslo Central Station to Tøyen, and then spread out into the suburbs. A loop line runs in a circle from northern Oslo city centre to the center and back. The loop line is called "Ringen" the ring in Norwegian.
With rolling stock from the 1960's, the Oslo metro used to be one of the most run-down in Europe, but it has now been fully replaced with new metro trains engineered by Siemens and designed by Porsche.
When entering a T-bane station, make sure to pick the correct platform: all stations except three on the loop line Sinsen, Storo and Nydalen have separate entrances and separate platforms for trains going west and trains going east. If you have a paper ticket, make sure that it is valid stamped before entering the train. If you have an electronic ticket, you should theoretically validate the ticket before entering the train; however this is not yet enforced rigidly but the ticket must still be valid (activated).
By taxi
Taxis are expensive. The minimum charge with most companies is at least 80NOK, increasing to a whopping 160 NOK late at weekend nights. Short central hops cost upwards of 100NOK, so if public transport still runs, use it. Taxis in Oslo as in most of Norway are frequently new, large and comfortable cars like Volvo or Mercedes. Most taxis wait for customers in a line in front of hotels or train stations, or you can order one by phoning one of the handful of taxi companies for an extra charge. You can also flag one from the street, or go to a taxi stand.
Several companies compete to have the most incomprehensible price structure. All taxi companies have a starting fee 0-160 NOK and a fee per kilometer that varies from 14-30NOK. These fees vary by taxi company and time of day. Usually, there's three different rates: The lowest one is the day rate, usually between 06.00 and 18.00. The next is the evening and night rate, usually 18.00-06.00 M-F and 06.00-18.00 Sa. The last rate is usually for Saturday after 18.00 till Monday 06.00, but different companies do have different time frames. Beware that some companies will operate with a special holiday rate helligdagstakst on public holidays, including the night before, which will result in staggering rates.
Taxi drivers in Oslo aren't a particularly jolly breed, but they usually do not speed too much, and taxi-crime towards customers is almost non-existent towards tax authorities, however, is a different matter. Sometimes a taxi driver will attempt to charge you extra for luggage, and some companies do have a surcharge for this. The price structure should be shown on a sticker inside the car, but is always in so small print, and with an overwhelming amount of details, you can't possibly decipher it. Another thing that often disturbs visitors is that the taxi drivers' name and license is not printed inside the car itself. If you encounter any problems, ask for a receipt which will help you identify the car later, or make a note of the taxi license number on the car roof.
All taxis accept Visa and Mastercard, and the card should be swiped in the meter at the start of the journey for card validation. The driver will usually keep the card on top of the meter so that you can keep an eye on it. If you are uncomfortable with this, it is possible to ask to get the card back, but the card needs to be swiped again when you arrive at your destination. Most meters are just swipe and sign, but some companies have EMV chip terminals where you'll need to authorize the charge with your PIN. There have been no known scams connected to credit card fraud in taxis.
Some people tip taxi drivers, or round the bill up to the nearest NOK 10, but taxi drivers do not generally expect tip - most people pay the exact amount by card anyway.
By ship
Boats run from Vippetangen near Akershus fortress to the islands in the Oslofjord, as well as from Aker Brygge to Bygdøy, with many major museums. The regular tickets are valid for local boats. Single tickets are sold on board for 50 NOK.
The departures, especially in evenings and winter, are infrequent, so make sure you don't miss the last one! Schedules can be found here: (http://ruter.no/Gallery/1...).
From Aker Brygge, there are also departures for Nesodden and Slemmestad. These run out of Oslo, and are not covered by the Oslo tickets. However, they provide a cheap cruise on the Oslofjord.
By Bus Or Tram
Trams and buses complement the metro network, and use the same tickets. They cover most of the city, and run from approx. 5AM to past midnight, on some lines up to 1AM. Two bus lines, 31 and 37, run all night, every day.
All tram lines run every 10 minutes during the day, and every 20 minutes at night and early morning 30 min at weekend mornings. The main lines cover parts of the city with no metro, and are an efficient way of getting around. The main, central tram terminal is at Jernbanetorget, where all lines converge.
Bus lines cover the rest of the city, as well as several ring lines. Nearly all central bus lines converge at Jernbanetorget. The most useful bus lines for visitors are buses 30, 31, 32, 34, 37 and 54, passing by Jernbanetorget and covering parts of the city with no tram or metro lines. Buses 20 and 21 provide central ring-line service, while buses 23 and 24 cover the highway ring road further out.
Nights after Fridays and Saturdays, buses cover parts of the city with varying frequency. All regular tickets are valid. More information and a map of the weekend night lines can be found online (http://ruter.no/en/Travel...). Most of these start or pass by the bus stops close to the Parliament building Stortinget and Jernbanetorget Oslo Central Station/Oslo S.
By car
For general information on driving in Norway, see Norway.
The major roads entering Oslo is also used for travel inside the city. In the eastern suburbs, road E6 is the main north-south corridor. East-west transport can be done on road E18 as well as Ring 3 running from E18 at the western city border to E6 in the eastern suburbs. The smaller and slower Ring 2 connects Skøyen in the west via Majorstua, Ullevål general hospital and Carl Berners plass to E18 east of the centre. The ring roads as well as other main roads are great for navigation.
Beware to always give way to trams and pedestrians, unless overridden by signs or traffic lights. Never challenge the tram, they have a long braking distance and will in any case give a loud, clear warning if you are obstructing. In some roundabouts the tram is driving straight through the island while cars must circle, be extremely careful in this type of roundabouts. Trams are not obliged to yield to pedestrians, while cars must. Park your car in safe distance from the rails as not to obscure the tram ask locals if unsure.
By bike
Except during the winter approx. Dec-Mar Oslo has a public bike service (http://www.adshel.no/oslo...). Just get a keycard at the tourist office 80NOK, valid one day or at the aforementioned web site before going to Oslo 90NOK for the whole season and you can get a bike at numerous places in the city. The bike can be used for up to three hours before you return it to any city bike stall. Once you have returned it, you are immediately eligible for a new one, so you can practically keep the bike all day long provided you check in and check out every three hours.