Originally Posted by
BikeLite
... , considerable research has identified that highlighting a cyclist’s biological motion can provide powerful conspicuity enhancements. Thus fluorescent leggings can offer a powerful and low-tech tool for enhancing bicyclists’ daytime conspicuity."
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When I have been driving a car at night and see people riding bikes in front of me where my headlights light up their pedal reflectors, the up and down motion of both pedals is very noticeable.
For that reason I have put reflective tape on left side crank arms on both sides on most of my bikes, my SPD pedals do not have reflectors and do not have a convenient way to add them. I bought some more tape, but have not gotten to the right side crank arms yet. That said, when touring, panniers would block some of that from being visible from behind or ahead, but I rarely have panniers on a bike after dark.
As far as leggings go, from behind my panniers would be in the line of sight from behind.