Today is “Högertrafikomläggningen” Day, but you may prefer to simply call it H-Day or Dagen H. On 3 September 1967, traffic in Sweden switched from driving on the left to driving on the right.

A picture paints a thousand words.

This image was taken by Swedish photographer Jan Collsiöö and is in the public domain in that country because it is non-artistic (journalistic) and was created before 1969.