Source: Wikimedia Commons. Author: Mynameisben123. Description: Oahu, Hawaii An Hawaiian Fire Knife dancer.
What does our extensive research into bicycle accidents underline about how to avoid accidents beyond practicing defensive bicycle riding skills and providing a novel excuse to avoid going on a diet? Be conspicuous! Anyone who plugs the search terms “night time bicycle safety“ into Google will no doubt soon be aware that reflectors insufficient for safe cycling at night. The most important reason for this is that reflectors are effective only when a beam of light shines directly on them. In the all too frequent situations when the head beams of vehicles whether from motor vehicles, bicycles or flashlights are not on, are burned out or do not shine directly on them, reflectors do not shine back and thus do not enhance the conspicuity of bicyclists.
Perhaps one of the largest and studies on bicycle safety from New Zealand underlined that the majority of bicycling accidents happened during the day.* This result makes sense when one thinks in terms of what the research community refers to as “exposure” i.e. a measure of when most of the events being studied (bicycle trips) occur. Because most bicycle trips occur during the day, most accidents (though much smaller in proportion than at night) happen during the day. Yes, you may be much more likely to be involved in an accident during the day, but not cetrus paribus, i.e. all things being equal. More significantly, if you have lights that can be seen during the day, like motorcycles and automobiles that are increasingly required to be equipped with daylight driving lights, that may also be helpful. As is the case of arms races, however, one side’s advantage is, to an extent, necessarily the other side’s disadvantage and cyclists are generally unfairly disadvantaged in the contest of conspicuity from lighting during the day and at night.** Most bicycles today come without generators (except in Germany where they are mandatory by law) and those with lights mounted (normally battery powered) are rarely on during the day.
* S J Thornley, A Woodward, J D Langley, S N Ameratunga and A Rodgers (2008), “Conspicuity and bicycle crashes: preliminary findings of the Taupo Bicycle Study”, Injury Prevention, 4;11-18.
** For more reading on this complicated subject and oftentimes contentious subject, see Pierce, Richard (2011) “Safety fears raised over mandatory daytime vehicle lights“, accessed 21 January 2013. For further views on this subject by Wouter Scholten, see: Daytime running lights (DRL), accessed 21 January 2013.