The Surface Transportation Board in the US has approved the Northern Rail Extension of the state-owned Alaska Railroad, which is expected to provide year-round freight access to military training grounds near Delta Junction.

The 130km (80 mile) extension will run from Eielson Air Force Base in Fairbanks to Delta and nearby Fort Greely.

The project is expected to finish in three years and cost nearly $700m, out of which the Department of Defense is contributing $100m.

The extension will also provide an alternative route to the Richardson Highway, which is the only means of transportation of commercial freight in the area south of the North Pole.