The idea is apparently, if the lane is narrow enough that the automobile would have to get into the other lane anyway, in for a penny, in for a pound. It is plausible that a rider in the middle of the lane is more visible than one riding 18 inches from the right edge. Reliably better?
Middle of the lane is a bad place to ride. You have to deal with oil, debris and NAILS!
The safe spot is really the right side vehicle tire track, all of the phantom nails have been soaked up already.