A recent paper published in Accident Analysis & Prevention titled “The relationship between visibility aid use and motor vehicle related injuries among bicyclists presenting to emergency departments” examines whether cyclists visibility aids reduce the risk of a motor-vehicle collisions in an Canadian context.
Cyclists Visibility Aids
The study looked at the use of nine “visibility aids” which were listed as:
- Helmet colour (black, white, red/orange/yellow, other, no helmet, unknown, light or dark)
- Reflective clothing
- Any reflective articles
- Front upper body colour (as per helmets)
- Lower body colour (as per helmets)
- Any fluorescent clothing
- Bike reflectors
- Headlight turned on
- Tail-light turned on
Cyclists Visibility Aids Study Context
The cyclists surveyed in this cyclists visibility aids study where cyclists injured in a collision with a motor-vehicle and assessed at one of the emergency departments in Calgary, Canada and three hospitals in Edmonton, Alberta, Canada. After exclusions to restrict the sample to those exposed to motor-vehicle traffic, the study sample was of 278 cases. As I understand it the cyclists completed a questionnaire.
Cyclists Visibility Aids Study Outcomes
Whilst the full cyclists visibility aids study should be reviewed in summary the authors found that:
- During daylight, white or a light colour on the front upper body reduced the odds of a bicyclist motor-vehicle collision.
- Surprisingly under dark conditions, red/orange/yellow clothing worn on the upper body, or the use of a tail light, increased the odds of a motor-vehicle collision. The use of a tail-light contributing to collisions seems rather odd on the face of it and I think the opportunity to look at this further (i.e., flashing versus non-flashing) was lost due to a poorly constructed study.
Of interest however is that the authors found a 90% reduction in the odds of hospitalisation when cyclists used two or more visibility aids. So this seems to suggest that a multi-faceted approach to visibility aids might be worthwhile, however as I note below the study really is lacking in-depth and this finding needs fleshing out. It should be treated with come caution in my view until that occurs in future studies.
The authors concluded with this comment:
Interpreted in light of the current evidence, our findings suggest that bicyclists may overestimate how conspicuous they are when using visibility aids and, as a result, may ride at times or in locations that increase their risk. Our data indicate that riding during weekday peak time, riding in dark conditions, at locations with a speed limit >30 km/h and riding for commuting purposes were associated with increased odds of a motor-vehicle collision. Therefore, if bicyclists intentionally choose to ride at these times and in these locations after donning fluorescent clothing, for example, any protective effect of such visibility aids may be overwhelmed by the increased risk posed by environmental influences.
In my opinion the paper is really lack in both its method (e.g., for example did not examine the impact of flashing veers non-flashing headlights, did not look at the use of headlights during the day, fails to support its findings) and in its findings. I don’t find the study of much use as it the authors show a high dependence on other studies to substantiate their conclusions..
Overall a disappointing contribution to our knowledge and in my view an opportunity lost.
A related study by Wood, Tyrrell, Marszalek, Lacherez, Carberry, Chu, & King (2010), Cyclist visibility at night: Perceptions of visibility do not necessarily match reality is more informative in my view and worth a read.
What are your thoughts on this Cyclists Visibility Aids Study?
Please do share you thoughts on the is study, on the use of visibility aids and your experiences in the comments box below.
Cyclists Visibility Aids Study Reference
Unfortunately Elsevier the publishers of Accident Analysis & Prevention do not allow me to share the full copy of the paper but you maybe to get access to it via your University library or public library system. The full reference to the article is:
Hagel, B. E., Romanow, N.T.R., Morgunov, N., Embree, T., Couperthwaite, A. B., Voaklander, D., & Rowe, B. H. (2014). The relationship between visibility aid use and motor vehicle related injuries among bicyclists presenting to emergency departments. Accident Analysis & Prevention, 65, 114-122.