The Conspicuity Benefits of Bicycle Taillights in Daylight

Abstract

Bicyclists risk being injured or killed in crashes with motor vehicles, even during the daytime. Therefore, cyclists must help approaching drivers detect and recognize their presence. The present study examined the conspicuity benefits of bicycle taillights during the daytime. Participants' eye movements were recorded as they searched for vulnerable road users in videos recorded from a driver's perspective in a moving vehicle. Five of the videos contained a bicyclist who displayed one of five taillight configurations. The distance from which each participant first glanced at the bicyclist was recorded, as was the distance from which the participant pressed a button to indicate that a bicyclist was present. The results indicated that the participants first fixated on the bicyclist at a distance that was 2.7 times greater than the distance at which they responded to recognizing the bicyclist. Additionally, the bicyclist was recognized from significantly greater distances when using a flashing or steady seat post-mounted taillight than when no taillight was displayed. These findings confirm earlier research that bicycle taillights can enhance drivers' ability to recognize bicyclists during daylight.

The Temporal Dynamics By Which Drivers Become Aware of Bicyclists Who Use Taillights In Daytime

“…In other words, taillights that are mounted to the seat post of the bicycle with or without lights on the rider's heels can help observers to recognize the presence of the bicyclist from farther distances. This finding adheres to the results of similar studies that assessed the benefits of taillights on bicyclist daytime and nighttime conspicuity (e.g., Blomberg et al, 1986;Edewaard et al, 2017;Edewaard et al, 2018;Edewaard et al, 2020;Koo & Dunne, 2012;Koo & Huang, 2015;Matthews & Boothby, 1980;Watts, 1984).…”

“…This can be interpreted as an encouraging finding because the First Glance, Final Glance Prior to Detection, and Detection distances were each greater than 200 m, which (for a vehicle traveling at 35 mph) would give a driver over 12 seconds to process the visual information corresponding to the bicyclist before they are adjacent to the bicyclist. These results are very similar to the results of the eye tracking experiment conducted by Edewaard et al (2018), which found that the distances from which participants detected a bicyclist displaying the same configurations in daytime videos of drive-bys of a bicyclist were not significantly different from each other.…”

“…Bicycle taillights can provide conspicuity benefits for bicyclists (Blomberg et al, 1986;Edewaard et al, 2017;Edewaard et al, 2018;Edewaard et al, 2020;Koo & Dunne, 2012;Koo & Huang, 2015;Matthews & Boothby, 1980;Watts, 1984). While taillights are conventionally mounted to the seat post, taillights have the potential to be more effective when mounted elsewhere on the bicycle or rider.…”

The Conspicuity Benefits of Rear-Facing Bike Lights in Daylight

“…Bicycle taillights can help observers to recognize bicyclists more easily and from farther distances during the daytime (Edewaard et al, 2019;Edewaard et al, 2018). While taillights are conventionally mounted to the seat post, taillights have the potential to be more effective when mounted elsewhere on the bicycle or rider.…”