Working Group 3: Impact Engineering

Bicycle Accident Reconstruction

Working Group 3’s investigations began with a review of the typical impact situations for a bicyclist. This proved to be a complicated endeavour, as accidents can happen in a nearly infinite number of ways, under a multitude of different conditions, including – but not limited to – rate of travel, weather conditions, angle of impact, the involvement (or not) of other parties, and more. There is a limited amount of valid data available, but enough exists to make preliminary evaluations of accident conditions, based on the results of six recognised studies.

WG3 table 1

Impact speed and angle from detailed accident reconstruction studies.

The six studies evaluate accident reconstructions based on the GIDAS database, the French Accident Database, and the simulation programme MADYMO. Parameters such as accident type (single fall or collision with car), rate of speed, angle of impact and road surface type were included in the studies. In total, data from 5,534 accident reports were evaluated, and 46 accidents were reconstructed.  

Although the ‘most common’ impact angle is still difficult to evaluate exactly, it is clear from the reconstructions that impact angles are usually far removed from the direct, 90-degree impact conditions under which helmets are currently tested. There remains a lack of additional, detailed accident reconstructions, which would provide a statistically based decision on the most common types of bicycle accidents. Based on existing data and literature review, Working Group 3 proposes to keep the shock absorption tests defined in EN 1078 and EN 1080, but to complement these with three angled (oblique) tests, using an impact angle of 45 degrees at a speed of 6.5 m/s.


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