In September 1967, all Swedish traffic had to change the habit of decades and swap to driving on the right-hand side of the road.
It brought them into line with most of the rest of Europe except for Britain and Ireland but caused a day of chaos. In 2016, Ashley Byrne spoke to Bjorn Sylven who remembered that day.
A Made in Manchester production for BBC World Service.
(Photo: First day of driving on the right-hand side in Stockholm. Credit: Keystone-France/Gemma-Keystone via Getty Images)