Leaving aside the much shorter Kaldidalur Route in the west, Kjölur -- which runs from Geysir and Gullfoss in the southwest to Húnaflói and Skagafjörður in the north -- is the most accessible, most trafficked, and least barren route through Iceland's highland interior. The highest point of the road, at 700m (2,297 ft.) above sea level, is in the valley between Langjökull and Hofsjökull, Iceland's second- and third-largest glaciers. Strictly speaking, Kjölur refers only to this valley, but the word commonly applies to the entire 165km (103 miles) course of mountain road F35. Kjölur is often called a "shortcut" to Akureyri, but this only makes sense if you're already near Geysir and Gullfoss -- and you have a 4WD car. In a regular car Kjölur is usually navigable, and all rivers are bridged, but your insurance will likely be voided.

The government has initiated talks with a private company to build a paved toll road through Kjölur. The new road would cut a straighter path and remain open all year. Supporters speak of increasing access to the interior, but Iceland's Travel Industry Association opposes the project, arguing that visitors entranced by the interior's unspoiled landscape don't want to hear trucks echoing across the plains.