Originally Posted by RobertHurst

That's right. I hope people aren't riding around out there thinking that their degree of visibility to motorists is determined by their distance from the curb. The implication being that a seemingly radical leftward position is radically visible. It ain't.

Lateral position on the roadway is not the magic bullet *for visibility.* I've been overlooked enough times in the middle of the left lane to know that lane position is a very limited tool for maximizing visibility. It is quite magical for other reasons however. Riders focused on maximizing visibility should, first of all, understand that the danger of being overlooked is ever-present, but that it comes substantially from the front and sides and is much weaker from the backside. The danger comes substantially from drivers and pedestrians who are about to enter the roadway from the sides, and drivers making left turns, and not nearly as much from following drivers (who have much longer to notice a cyclist who is more or less where they are already looking). Those serious about maximizing visibility to the road users most likely to overlook should first of all slow down (the probability of being overlooked by side traffic is more dependent on rider speed than anything else in my opinion); then use day glo clothing and lights. Maybe wild arm gesturing. But expect to be overlooked anyway, and use strong leftward lane position to maximize buffer space between yourself and those who are most likely to encroach. Riding left will greatly ease your travels in congested areas, and gives a little leeway space to move into to facilitate passing if necessary, in the give-and-take dance of urban cycling. When traveling on a roadway without much possibility of side traffic or wayward pedestrians, with good sightlines and a decent shoulder, the need for established leftward lane position all but disappears.