While the vast majority of travelers prefer to get around the island by car and even often with a hefty 4x4 to conquer the off-road trails, some prefer to be driven around, and the bus is a great option.
The bus network in Iceland is quite vast and covers even the most remote destinations such as the Northwestern fjords and the highlands.
BSI is the main transport company in Iceland. Located in Reykjavik, it manages the 3 main companies that serve the entire island: Straeto, Reykjavik Excursions and Sterna. Keep in mind there are also smaller private companies that manage a particular destinations or regions.
In winter, generally speaking, the Icelandic bus network will only cover the main destinations around the Ring road. Destinations further inland, which are less accessible in winter, are restricted to vehicles made for off-road travel.
Straeto is the public company with the largest network and operates all year round, where the other two operate exclusively in summer: one from June to August and the other from May to October.
Straeto is the company that connects the “big cities” such as Akureyri or Reykjavík and goes almost all the way around the island except for the far east where you can rely on the equally capable local company, Svaust in this case. Reykjavik Excursions takes care of specific tourist sites, including in the highlands, via 4x4 buses equipped to cross the fords.
There is a site that brings all this data together with a convenient map of all the routes by all providers, which makes it easy to organize your trips: http://www.publictransport.is. By clicking on a line, you can see the company (color) offering the trip in question.
Travelling by bus in Iceland will save a lot of money, but at the cost of having less freedom than with a car. Bus tickets can be purchased at the BSI bus station, directly on the Internet or from the bus driver.
Depending on the trip, you can buy single tickets (quite expensive) or packages, called “passports.” Depending on the company offering the passport, Sterna or Reykjavik Excursions, different options are available.
Passport contents change all the time, adapting to the market. For a long time, there was a “Full Circle” package that no longer seems to be offered. You should regularly check their site to see which passes are available.
In summer, Reykjavik Excursions offers Iceland On Your Own packages with prices around 14,000 ISK depending on the number of days. Sterna also offers packages ranging from 14,000 to 19,000 ISK to travel the south or the highlands.
But keep in mind that these smaller networks sometimes only connect the more remote areas twice a day, so you really can't be late!
You should know that most of these companies have bike-racks for you to bring your mountain biking gear, generally for around 4,000 ISK.
You can also leave luggage at the BSI bus station in storage to avoid transporting everything all the time, which is a convenient service with pre-chosen pick-up dates. You can also have bulky items sent to a site such as a shelter on a given date, so if you have sports gear or anything you need in the field, it can always be planned and arranged.
Passengers on each flight arriving at Keflavik Airport can enjoy a shuttle service to the capital offered by the Reykjavik Excursions bus company. The journey takes approximately 45 minutes connecting the airport car park and the Reykjavík bus station.
All you have to do is head right outside the airport exit and you will almost always find a Flybus present. It is recommended to book in advance to avoid queueing, which you can do online. You can also book a minibus for smaller groups.