Demonstrations of Retroreflectivity Help Road Users Appreciate Retroreflective Markings

Retroreflective surfaces reflect light back towards the source of the illumination. All road users benefit from retroreflective markings in the roadway environment, as their use is required on road signs, on lane delineators, and on large trailers. Although a large body of evidence indicates that retroreflective markings can greatly enhance the conspicuity of pedestrians and bicyclists, these road users are largely unaware of strategies to enhance their own conspicuity at night. Here, 47 observers in an online study predicted how bright three stimuli would appear during a demo designed to highlight retroreflectivity. They did not expect a retroreflective swatch to be any brighter than the diffuse reflector. Their brightness predictions were consistently too high for specular and diffuse reflectors, but not for a retroreflector. This indicates that the observers failed to recognize and appreciate the special optical characteristics of retroreflectors. Educational interventions could be particularly useful in this domain.