The legal minimum distance for overtaking depends on whether the road is located within or outside a built-up area.
The OpenStreetMap way tag "zone:traffic" basically provides this information. However, it is not used for annotation in many regions. Currently, the distance limit is chosen as 1,5m by default, which is thus wrong often.
The proposed solution is to introduce a hand-crafted or trained binary classifier which predicts from existing way properties such as speed limits whether this is an urban or rural road and annotates ways accordingly. This prediction is always outvoted by the "zone:traffic" tag.