Shelagh Fogarty is Leading Britain's Conversation.
3 September 2017, 16:15
This is what happened when Sweden switched from driving on the left to the right-hand side, 50 years ago today.
The Scandinavian country followed 70% of the world in driving on the right on 3rd September 1967.
And the moment it happened caused predictable chaos, as shown by the picture above from Kungsgaten in Stockholm shortly after it happened.
But remarkably, that day and the day after that, there were no deaths on the roads of Sweden and there were substantially fewer collisions.
But that reduction soon reverted to normal and is believed to have been caused by people taking more care over driving as they got used to the new rules.
When roads were built, the rules were created to drive on the left in order for people to carry weapons in their right hand - as most people were right handed.
However, this was changed when horse and carts became more common to allow cart-drivers to whip their horses with their right.
The video below explains more: