Seasonal variations in conspicuity of high-visibility garments

Abstract

A naturalistic, daytime field study was conducted to investigate the effects of garment color, the amount of background material, driver age, and season on the conspicuity of high-visibility safety garments. Subjects drove an instrumented vehicle along a 29-km route once in the summer and again in the fall. Their task was to detect pedestrians wearing high-visibility garments. Distances at which pedestrians were first detected were recorded. All of the challenges normally encountered when driving on public roadways were present, thus providing a more ecologically valid level of workload than provided by test-track or static evaluations. The results show that the amount of background material and season significantly affected the detection distance of a pedestrian wearing a fluorescent-colored garment. There was no significant interaction of season and garment color. The analyses suggest that color contrast with natural backgrounds might contribute more to the conspicuity of fluorescent red-orange garments than the corresponding luminance contrast. On the other hand, luminance contrast might contribute more to the conspicuity of fluorescent yellow-green garments than color contrast.