Dagen H (H for Högertrafik, Swedish for right-hand driving), or "H Day", on 3 September 1967 was the day Sweden switched from left-hand driving to right-hand driving (via).
The main reasons for Sweden's switch to driving on the right were that its neighbouring countries drove on the right and that most of the people in Sweden drove left-hand drive vehicles (via).
As the question whether driving on the left or on the right becomes part of a cultural tradition, the change was not a popular one. In fact, it had been voted down by a majority for about forty years before Dagen H (via). It is also our culture that gives us an idea of who is driving on the right side or on the wrong side of the road ...
The rule of the road is a paradox quite,
For if you keep to the left, you're sure to be right.
Highway Act from 1835, UK
On 3 September 1967, all traffic signals were wrapped in black plastic, all non-essential traffic was banned for a few hours, all vehicles had to stop at 04.50, change to the right and continue driving at 05.00 (via).
Most of the bus stops were moved to the other side of the streets, most of the trams were replaced by new buses with doors on the right-hand side. Vehicles also needed adaption (via).
Left or right are relative directions, egocentric coordinates. The tendency to use egocentric (e.g. left-right) vs. geocentric (e.g. north-south) coordinates varies as spatial frames depend on which language (and cultural) community one belongs to. English, for instance, rather uses egocentric, body-defined coordinates, e.g. "The cup is to the left of the bowl." Tseltal Mayan (spoken in Mexico), for example, prefers geocentric coordinates although the words "left" and "right" are part of the language, e.g. "Pass me the cup to your north." (Li et. al, 2011).
A campaign prepared Sweden for the change. There were Dagen H logos on many different items such as underwear and milk cartons, songs dedidated to the day and some more initiatives (via).
- Li, P., Abarbanell, L., Gleitman, L. & Papafragou, A. (2011). Spatial reasoning in Tenejapan Mayans. Cognition, 120, 33-53.
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