Innovative motorcycle headlight design as a short-term solution for improving motorcycle visibility

ISAL 2015 - International Symposium on Automotive Lighting, Darmstadt, ALLEMAGNE, 28-/09/2015 - 30/09/2015; The most frequent motorcycle accidents involve another vehicle violating the motorcycle's right-of-way at an intersection. In-depth accident studies have shown that perceptual errors made by other vehicle drivers are a very frequent cause of motorcyclists' accidents and fatalities. Two kinds of perceptual errors can be distinguished. The first one is no or late detection of the motorcycle, which is mainly due to its low visual conspicuity (especially because of their small size). The principal safety measure in the past has been the use of daytime running lights (DRLs) by motorcycles, which became compulsory in the seventies in many countries. This conspicuity advantage of motorcycles as the only vehicles with DRLs is presently getting lost by the growing use of DRLs by cars as well. In an earlier study we have shown that car DRLs are actually competing light patterns that create visual noise and decrease the detectability of motorcycles. The second kind of perceptual error, less well known, is the misperception of the approaching motorcycle's speed (which is underestimated) and time-to-arrival (which is overestimated) that also contributes to accident occurrence. In order to reduce motorcycle accidents, and especially to improve motorcycle perceptibility (both detection and speed perception) by other vehicle drivers, ITS based on vehicle-to-vehicle communication will probably provide effective long-term solutions (>15 years). But until then, other solutions have to be found and could quite easily be implemented, by considering innovative headlight configurations for motorcycles. In two simulator studies, we tested various motorcycle headlight configurations, intended for remedying simultaneously the two perceptual errors made by other vehicle drivers. The impact of different headlight configurations (using colour coding and additional lights) was studied in the presence of visual distractors (car front lights: only LEDs, only dipped beams, LEDs and dipped beams) and in different illumination conditions (nighttime, dusk and daytime conditions). The results of the first study on motorcycle motion perception indicated that headlight configurations that accentuate the vertical dimension of the motorcycle (additional lights on the fork and on the rider's helmet) led automobilists to adopt larger safety margins towards motorcycles. The advantage provided by the innovative headlight configuration showed up especially at low illumination conditions (night and dusk) where the motorcycle outline was not visible or difficult to perceive. On the contrary, a triangular design (with two additional lights on the handlebars) showed no significant improvement.The findings of the second study on motorcycle detection showed that additional yellow lights (on the motorcyclist's helmet and the motorcycle fork) significantly improved motorcycle conspicuity and produced the best motorcycle detection performance, even in the presence of a great number of competing car headlights (when LEDs and dipped beams were lit at the same time). When combining the results of our studies, we suggest a motorcycle headlight configuration that consists in one white central headlamp, an additional yellow light on the helmet and two additional yellow lights on the fork. This ergonomic solution has the potential of successfully counteracting the two kinds of perceptual errors made by other vehicles drivers.