The Helmet Update
Volume 31, #6, October 7, 2013
All issues index
Study: Helmets do not change passing safety
In 2007
we disputed
the findings announced by Dr. Ian Walker that his study had proven that riders with helmets were given less safe
passing clearance by cars on roadways. We did not think his data actually showed that, since average passing distances
were more than one meter, helmet or no.
A new study has gone beyond our comments and concluded:
Results
The previously observed significant association between passing distance and helmet wearing was not found
when dichotomised by the one metre rule. Other factors were found to be significantly associated with close passing
including cyclists' distance to the kerb, vehicle size and city of observation (Salisbury or Bristol, UK). P-values from
bootstrap samples indicate the significance of helmet wearing resulted from an overly large sample size.
Conclusions
After re-analysis of Walker's data, helmet wearing is not associated with close motor vehicle
passing. The results, however, highlight other more important factors that may inform effective bicycle safety
strategies.
Here is
the full study, by Jake Olivier and Scott R.
Walter
The Helmet Update - Bicycle Helmet Safety Institute
Randy Swart, Editor
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Arlington, VA 22204-1419 USA
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