Why Sweden Changed Driving Sides Overnight

Jan Collsiöö — Så var det. Public Domain.

September 3, 1967, was a big day for Sweden. Högertrafikomläggningen, or more simply, Dagen-H. It was the day the country switched from driving on the left to the right side of the road.

It was, predictably, absolute chaos, but the act of switching sides isn’t the most surprising part. It’s that the switch happened in 1967 when there were 1,976,248 registered vehicles Sweden. With that many cars on the road, switching sides was a logistical nightmare. It took a month and military aide to change signs and markings overnight, not to mention manage the nearly two million drivers grappling with the change. So if everything was set up for left-hand driving, why change sides at all? Why did Sweden change driving sides in 1967!?

To get to the bottom of this one, we need to talk about ancient Rome, the British Empire, Napoleon, the Second World War, freight transport, and the Ford Model T.

If you’re living in North America, most of Europe, most of South America, and large parts of Asia and Africa, you’re accustomed to sitting on the left side of the car and driving…