Sweden voted 83 percent to keep driving on the left, then switched anyway
A milk carton, a pop song contest, and 350,000 road signs pulled off overnight — one country's answer to losing a democratic vote it had already won.
In 1955, Sweden held a referendum on whether to switch from driving on the left side of the road to the right, matching Norway, Finland, and the rest of continental Europe. Eighty-three percent of voters said no, keep the left. It should have ended there.
It didn't, because the referendum was non-binding and the underlying problem hadn't gone anywhere: more than 90 percent of Swedish cars were already left-hand-drive, built for right-side traffic, which meant drivers were straddling narrow two-lane roads peering around their own dashboards to see oncoming cars. Head-on collisions were common and the country's fleet of vehicles was projected to nearly triple within a decade. In 1963, the parliament simply overruled the public and scheduled the switch for 3 September 1967 — a date that became known as Dagen H, or H-Day.
The logistics were enormous. Around 350,000 road signs had to be moved or replaced nationwide, 20,000 in Stockholm alone. Every intersection got a shadow set of signals wrapped in black plastic, unwrapped by crews working through the night before the switch. Sweden ran a public-information campaign for years beforehand, printing the Dagen H logo on milk cartons and even underwear, and held a national songwriting contest for the occasion — the winning entry, played constantly on the radio, was called "Keep to the Right, Svensson."
On the morning itself, all non-essential traffic was banned before 5 a.m. so the whole country could physically move to the other side of the road at once. It went off with barely a hitch. Democracy had already voted against it — the traffic just hadn't gotten the memo.