Vehicular cycling advocates recommend a number of ways to increase passing distances between cyclists and overtaking motor traffic.
One is defensive driving on the bicycle; if the travel lane is narrow, then riding closer to the center of the lane encourages drivers to "unstick" from the lane and move into the next lane. I ride near the center of the lane for about a third of my commute, and rarely get passed closely. This kind of defensive driving is not a "rule of the road" for cyclists, but exploiting it requires that cyclists be treated as drivers equally entitled to the travel lane as other drivers, and thus is related to vehicular cycling advocacy against regulation efforts to force cyclists to stay out of the way at all times.
Another is education and enforcement of motorists about safe passing distance.
The third is wider lanes. If the lane is adequately wide, close passing is rare. I never get passed closely in a 16' lane, and rarely in a 14' lane.