Using Motion Perception to Improve the Nighttime Conspicuity of Bicyclists at Street Crossings

Abstract

Recent literature indicates that active lighting, when strategically positioned, improves bicyclists\u27 conspicuity at night. Road cyclists are unique among other vulnerable road users in two ways: 1) they can leverage their own biological human motion and mechanical bicycle motion when using conspicuity solutions; 2) their visual surface area shown to approaching traffic is greater when viewed from a right angle (i.e., 90 degrees) than from the front/rear. However, research has not yet identified how to utilize these factors to maximize conspicuity. This project investigated the conspicuity benefits of using various configurations of six LEDs on a cyclist\u27s body and bicycle. Experiment 1 quantified participants\u27 responses to video recordings of a nighttime drive that featured a test bicyclist. Experiment 2, a nighttime study on a closed road, quantified participants\u27 subjective ratings of bicyclist conspicuity at night. The findings from these studies confirmed that capitalizing on drivers\u27 sensitivity to patterns of motion can significantly enhance bicyclists\u27 nighttime conspicuity when viewed from the side. Particularly effective is highlighting the rotating motion of a bicycle\u27s wheels, allowing drivers to quickly and easily identify bicyclists