Visibility: it's all in the legs

A new report has again confirmed the powerful visibility impact of fluorescent and/or reflective ankle bands fitted to bike riders.

The study is one of a number to report that drivers recognise bike riders with the leggings much earlier and at further distances than other visibility aids.

This new study examined whether fluorescent clothing, popular with many riders, improved visibility to drivers in open road conditions in daylight.

(Fluorescent fabric is of no benefit at night at it requires UV light for activation).

Drivers were sent along streets and asked to report when they observed a bike rider, who may have been wearing black jacket and leggings, or fluorescent jacket and leggings, or a combination.

The riders were pedalling on randomly positioned stationary bicycles in order to enable accurate measuring of distance and time.

The surprising finding was that drivers recognised cyclists in black jackets just as readily as those in fluorescent jackets, that is, riders in fluorescent jackets were not more visible.

But if riders were wearing fluorescent leggings, they were recognised 3.3 times further away.

“The finding that fluorescent yellow leggings can provide a dramatic enhancement to bicyclist conspicuity is, we believe, a consequence of highlighting the bicyclistʼs pedalling motion”, the researchers said.

“The rhythmic up-down movements of a cyclistʼs lower legs uniquely specify a pedalling motion that is visually distinct from, for example, a pedestrian walking or jogging.

“Further, considerable research has identified that highlighting a cyclistʼs biological motion can provide powerful conspicuity enhancements.

“Thus fluorescent leggings can offer a powerful and low-tech tool for enhancing bicyclistsʼ daytime conspicuity.”

The findings were published in the Proceedings of the Human Factors and Ergonomics Society.

Bicycle Network has long recommended reflective ankle bands as a powerful visibility enhancement at night, and now there is convincing evidence that they are also effective during daylight.

Riders should be making use of the human eye’s perceptual sensitivity to biological motion.

The reason why fluoro vests, jackets, backpacks and helmets don’t make you more visible is that they are on the upper body and there is no biological motion for the eye to detect.