* Sparse, mostly rural population (with an unique culture).
* "2+1" roads, which discourages meaningless overtaking or competing. (But I don't buy it as the single cause).
* Roundabouts instead of crossroads with traffic lights. (My bet this is one of the most important factors).
* Special reserved lane for doing left turns to secondary roads.
* Lots of street lamps (Sweden is famous for illumination and urban development).
* High percentage of expensive, very good quality cars (lots of Volvos) which kept well-maintained.
* 40 km/h speed limit in most small towns.
Together it works. Basically a complex phenomena is a weighted sum of multiple different causes - cultural (tradition), economical, social (current "normals"), technological, etc. with "random variables". Such simple model could explain it to some extent.
I am in Sweden now, and I drive a classic Volvo.
* "2+1" roads, which discourages meaningless overtaking or competing. (But I don't buy it as the single cause).
* Roundabouts instead of crossroads with traffic lights. (My bet this is one of the most important factors).
* Special reserved lane for doing left turns to secondary roads.
* Lots of street lamps (Sweden is famous for illumination and urban development).
* High percentage of expensive, very good quality cars (lots of Volvos) which kept well-maintained.
* 40 km/h speed limit in most small towns.
Together it works. Basically a complex phenomena is a weighted sum of multiple different causes - cultural (tradition), economical, social (current "normals"), technological, etc. with "random variables". Such simple model could explain it to some extent.
I am in Sweden now, and I drive a classic Volvo.