Why do Countries with Non-Existent Helmet Usage Have Lowest Rates of Bicycling Deaths?

Drivers of cars are less likely to hit walkers and bicyclists if more people walk and ride bikes.  

1. When more people walk or bicycle,the less likely any of them are to be injured by motorists.

Traffic engineering and legal policies should focus on modifying motorist behavior not cyclist behavior.


2. Countries with the lowest bicycle fatality rates also have the lowest helmet usage rates.

According to one study, U.S. 38% of U.S. bicyclists wear helmets and the U.S. has by far the highest number of bicyclist deaths per km cycled.  Interestingly, in the Netherlands, 0.1% of bicyclists wear helmets and bicyclists there have the lowest rate of death per km cycled.  See below.

Sources

Cycle helmet wearing:
Netherlands, Denmark, Finland, Sweden (EC, 1999); Germany (Pucher and Dijkstra, 2000); UK (Bryan-Brown and Christie, 2001); USA & France (Paris) (Osberg and Stiles, 1998).

Cyclist deaths:
EU (CIT, 2001); France (Carre, 1995), USA (Pucher and Dijkstra, 2000).

Cycle Percentage of trips:

Flanders cities (ECF, 1997); USA, Canada, France, Italy, Austria (Pucher and Dijkstra, 2000); UK, Norway, Switzerland, Sweden, Denmark (EC, 1999); Germany (Bracher, 2003); Netherlands (Welleman, 2002)

3. People who bike with a helmet may ride faster and drivers give less space when passing helmeted cyclists.


Drivers pass closer when overtaking cyclists wearing helmets than when overtaking bare-headed cyclists, increasing the risk of a collision, the research has found.
Dr Ian Walker, a traffic psychologist from the University of Bath, used a bicycle fitted with a computer and an ultrasonic distance sensor to record data from over 2,500 overtaking motorists in Salisbury and Bristol.
Dr Walker, who was struck by a bus and a truck in the course of the experiment, spent half the time wearing a cycle helmet and half the time bare-headed. He was wearing the helmet both times he was struck.
He found that drivers were as much as twice as likely to get particularly close to the bicycle when he was wearing the helmet.
Across the board, drivers passed an average of 8.5 cm (3 1/3 inches) closer with the helmet than without
The research has been accepted for publication in the journal Accident Analysis & Prevention.


4. Bicycle helmets may increase chance of neck injury in a crash because they may catch or drag on concrete surfaces causing the head to decelerate at a faster rate than the rest of the body.

Hodgson VR. Impact, skid and retention tests on a representative group of bicycle helmets to determine their head-neck protective characteristics. Detroit, MI: Wayne State University, Department of Neurosurgery, 1990.