Day in Sweden when the change from left-hand traffic to right-hand traffic occurred
via Wikipedia infobox
Kungsgatan, Stockholm, 3 September 1967, at or around the moment of transition at 5:00 AM, on the morning when Sweden changed from left-side traffic to right-side traffic
Dagen H campaign logo Left-hand traffic in Stockholm in 1966
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).