Before 22 November 2014, getting from Mosjøen out to the coast meant the old route along the Vefsnfjorden - narrow, steep and twisting, cut into the fjordside south of Tovenfjellet, the kind of road that is merely tiring in July and genuinely unpleasant in February with a lorry coming the other way. County Road 78 is the artery between inland Helgeland and Sandnessjøen on the coast, and it was not behaving like one. The tunnel took eight kilometres out of the route and between ten and twenty minutes off the drive. More to the point, it took out the weather. A tunnel does not ice over, does not slide, and does not close because visibility has dropped to nothing over an exposed shoulder above the water.

Preparatory work started on 4 January 2010. The two faces met on 8 February 2012, and the finished bore opened almost three years later, on 22 November 2014: 10,665 metres, one lane in each direction, an 8.5-metre carriageway and 4.6 metres of clearance overhead. It is the longest road tunnel in Northern Norway. Driving it takes something over ten minutes at the limit, and the experience is what long Norwegian tunnels always are - a steady procession of lights, a slow shift in air temperature, the odd widened bay for breakdowns, and a curious loss of any sense of the mountain above you. Then daylight, and an entirely different landscape from the one you left.

The financing tells you how these projects actually get built in Norway, which is rarely by one party writing one cheque. Nordland county carried much of the capital cost. The state contributed. Money that had previously been spent subsidising ferry operations was redirected into the fixed link, on the logic that a crossing you no longer need to run is a crossing you no longer need to fund. Regional development funds went in. And the balance is being recovered from drivers through a toll, which is capped at twenty years if the revenue targets are met. That is the arrangement Norwegian motorists know well: you pay for the tunnel every time you use it, until one day you do not.

Helgeland is a difficult shape. It covers something like 18,832 square kilometres and holds only about 79,000 people, distributed among four towns - Brønnøysund, Mosjøen, Sandnessjøen and Mo i Rana - and a long scatter of islands and fjord-head settlements between them. Fjords cut deep inland, water interrupts nearly every direct line, and Mosjøen inland on the railway and Sandnessjøen out on the coast sit close on a map and far apart in practice. Every fixed link built here does the same quiet thing: it converts a journey people used to plan around into one they stop thinking about. The hospital, the college, the job and the airport on the other side of the mountain all move into range - and on this coast the airports matter, because Widerøe's small fields at Kjærstad and Stokka are how people here reach Bodø, Trondheim and Oslo. Under fifteen hundred vehicles a day is not much traffic by any national standard. For the communities at either end of Tovenfjellet, it is most of a working region moving back and forth.