Meanwhile Lars Magnusson adds that a more general “culture of conformism” and trust in authorities prevalent in Sweden at the time helped enable the shift in public opinion.

“The media was at that time less critical and they were reporting what the experts told them and if the experts said that this would not be very costly and it would benefit everybody, well, the media would accept that and I suppose the public would accept it as well.”

Magnusson believes that as well as being important for Sweden’s global reputation, when viewed as part of the Nordic nation’s wider efforts to be seen as a major player in Europe, the switch might potentially also have had other longer-term costs and benefits such as increased trade and transportation from other parts of the continent. However, this broader economic impact is, he argues “difficult to estimate” since the changeover occurred “during a period where the economy was growing a lot - and GDP - each year, so it is difficult to distinguish the possible benefits on trade and transport”.

Future lessons

So could Sweden pull off anything like Dagen H today?

Recently ranked top in Europe in Bloomberg’s global innovation ranking, with a transport infrastructure quality above the EU average and one of the region’s strongest digital economies, the Nordic nation would certainly have a head start should it decide to embark on a similarly disruptive transportation project.

But the prevailing sentiment among those who’ve studied Dagen H closely is that today’s political, economic and media climates would present numerous fresh challenges to those that existed at the time Dagen H.

Peter Kronborg’s key argument is that ministers and public authorities would struggle to shift public opinion and shape a new consensus so dramatically. He says that “everything about Swedish society became a little more individualistic” just a year after Dagen H, in the wake of student radicalism and counter-culturism across Europe, and he believes that today the Swedish public would be outraged if politicians went ahead with a project so vehemently opposed in a referendum.