Edewaard et al. 2020, fluorescent biomotion clothing and daytime conspicuity

Controlled study (Accident Analysis & Prevention) of how fluorescent clothing affects when drivers recognise a cyclist in daylight. Fluorescent material worked in daylight, and worked best on the moving limbs: a fluorescent jersey plus fluorescent leg covers was recognised about 3.3 times farther away than the fluorescent jersey alone. This confirms the split that matters for kit choice: fluorescent colours help in daylight and dusk but do essentially nothing in the dark, where retroreflective material is what works. It also reinforces the biomotion principle across both lighting conditions, since the high-visibility element belongs where the limbs move. On cyclists, not runners.