Sweden changed the entire country from left-hand to right-hand driving in a single morning in 1967 because nearly all neighbouring countries already drove on the right and most Swedish cars had left-side steering, making overtaking on its old roads dangerously difficult.

Sweden successfully transitioned to right-hand traffic on September 3, 1967, during Dagen H. This major traffic reform involved years of planning and extensive public education campaigns. The change aimed to improve road safety and align with neighboring countries’ driving practices. Despite initial public opposition, the government prioritized safety and international conformity. The operation demonstrated the effectiveness of careful planning and public awareness in large-scale policy changes.