torsdag 5 mars 2009

Bicycle helmet debate: the Stockholm experience

Bicycle helmets are a very controversial issue among cyclists. One side of the debate says they save lives. The other says they only prevent minor injuries, and that as helmet wearing rates increase, cycling rates decrease (see graph). Lower cycling rates actually increase accident rates [1]. There's also the health aspect. Few people have the discipline to exercise regularly in their free time. Cycling or walking to work and school is a way to get exercise without making special time for it.


Experience from Stockholm contradicts the graph above. Both cycling and helmet-wearing have both risen strongly between 1995 and 2005.

The three lines depict helmet-wearing rates across three sections in Stockholm. Source: Cykelräkningar 2008

Left scale: red = deaths, yellow = seriously injured, green = minor injury. Right scale: blue line = number of cyclists. Source Stockholms Cykelplan 2006

This suggests that Stockholm is bucking the trend shown in the first graph: it has a rising helmet-wearing rate, falling injury and death rate, and a rising number of cyclists.

There are two qualifiers: one, fewer than 10% of all journeys in Stockholm are done by bike (sorry, don't have a source for that right now). That's lower than the national rate and much lower than cycling cities like Amsterdam or Copenhagen, where 30%-40% of all journeys are done by bicycle.

The other qualifier is that the helmet-wearing rate has been flat during the past four years, while the number of cyclists has continued to increase strongly. That might point to the effect of internet helmet debates. It might also be that as cycling grows and thus becomes more mainstream, people do not see themselves as "cyclists", just ordinary people getting around.

The debate will surely go on. Here's one of the latest salvoes:
Copenhagenize: Bicycle Helmets - Today's Bloodletting

[1] Safety in numbers: more walkers and bicyclists, safer walking and bicycling

Inga kommentarer: