Beep, Beep

It was total chaos on the first morning after Sweden changed from driving on the left side to driving on the right, 1967. The official name for the day was Högertrafikomläggningen. A complicated name for a complicated task. What is the point of switching sides like this?
Is there a scientific formula that says driving on one side is less likely to bring forth an accident? If that is the case, then this would make sense but we aren’t going to go and try to find all the specifics for this one, just know we think it’s a bit strange without great reasoning.