[mkonecny]

One of the arguments is flawed:

> According to a 2006 French study, pedestrians are 1.4 times more likely to receive a traumatic brain injury than unhelmeted cyclists.

To fails to take into account that almost everyone walks, but very few cycle. The fact that it's only 1.4 times greater goes to show how common cycling head injuries actually are.

[Jemaclus]

Came here to point this out. This is a wildly popular argument for no-helmeters, but it's just flat out inaccurate. If you control for the percentage of people who drive, walk, and cycle, the percentage of head injuries from walking would pale in comparison to head injuries from cycling.

This is like the statistic that says that 80% of all automobile accidents happen within 10 miles of home. It's not because the area around your home is more dangerous, it's because you drive near your home more than you drive anywhere else. It's basic statistics.

The reason car drivers don't wear helmets is because of the insane number of safety features that are built into a car, from seatbelts to airbags to varying strengths of materials, that bikes simply don't have. If another car hits your car, a number of things jump into play to save your life. If a car hits you on your bike, you're gonna have a head injury at a minimum.

[nikisweeting]

THEY DO CONTROL FOR PERCENTAGE!

read the paper he quoted (emphasis mine):

"The severe TBI of 1238 patients were described. The annual incidence and mortality of severe TBI were, respectively, 13.7 per 100,000 and 5.3 per 100,000. The fatality rate increased from 20% in childhood to 71% over 75-year-old. Compared to restrained car occupants, the odds ratio for having a severe TBI was 18.1 (95% confidence interval, CI = 12.8–25.5) for un-helmeted motorcyclists, 9.2 (95% CI = 7.5–11.3) for pedestrians, 6.4 (95% CI = 4.7–8.8) for un-helmeted cyclists, 3.9 (95% CI = 3.1–4.8) for unrestrained car occupants and 2.8 (95% CI = 2.2–3.5) for helmeted motorcyclists."

http://www.sciencedirect.com/science/article/pii/S0001457505...

[Jemaclus]

Per 100,000 what? People who cycle? People in general? Patients with head injuries?

[brianbarker]

no-helmeters??

Of course something like that exists. Of course there's a group of people up in arms over helmet use.

Of course. Fuck me, nothing should surprise me anymore.

[Tomte]

They are a rather big and rabid group on Germany.

Another argument by them: sure, having your skull split open when falling and hitting the head on the pavement is bad, but it's really bad when you're falling and instead of a clean hit, your neck is subjected to particularly strong rotational forces due to the helmet enlarging your head, thus moving the point of impact outwards.

They are a nasty bunch.

[stevenh]

You supplied pejoratives, but not a single counterargument.

[Tomte]

I did: having your skull cracked open and your brain distributed on the pavement is certainly worse than having some strain put on your neck.

Both can be lethal. The former is very much so, the latter usually not.

No-helmet crowd claims the severity is the the other way around.

[colanderman]

I don't glean the same meaning you do. To be clear, you seem to be interpreting that statement as:

number of pedestrians injured = 1.4 × number of cyclists injured

while it reads to me as:

chance of injury while walking = 1.4 × chance of injury while cycling

which invalidates your point.

[Arelius]

It's hard to tell from the abstract alone...

  9.2 (95% CI = 7.5–11.3) for pedestrians, 6.4 (95% CI = 4.7–8.8) for un-helmeted cyclists

but to me, it looks like the number is

chance of traumatic brain injury as a pedestrian in an accident = 1.4 x the change of traumatic brain injury as a un-helmeted cyclist in an accident.

This seems to not at all take into account the probability of getting into the accident in the first place, which really makes the argument pretty moot.

[justinpaulson]

As much as I disagree with his entire premise, he does give the number per million hours travelled right after that statistic.

Cyclist - 0.41 Pedestrian - 0.80 Motor vehicle occupant - 0.46 Motorcyclist - 7.66

This does not mean I agree with his argument at all, and in fact it is pretty flawed logic to not do something that gives you 85-88% less chance of serious brain injury just because other activities may be more dangerous.

[xxgreg]

Does this mean you will now wear a helmet while driving, because it gives you 85-88% less chance of serious brain injury?

[justinpaulson]

I am thinking about it, actually. My wife's mother died from a head injury in a car (in the 90s with no air bags). I hadn't thought about wearing a helmet in a car much until reading this, but my car is also equipped with air bags both in front of and beside me. Most of the statistics in this article were before side curtain airbags were as common, and the pie chart is from the 70s when air bags were not very common at all. So I have basically purchased a vehicle that has a lot of the helmet functionality built in. I would guess wearing a helmet with full air bags is probably more dangerous than not wearing one.

[jackpirate]

This same fallacy appears in almost all the statistics he cites.

[jrockway]

The usual control is "number of accidents per person-hour". It's really irresponsible to give data without that context.

[nikisweeting]

If I understand correctly, your counter-argument is that this statistic is has no bearing because they fail to divide the total number of Traumatic Brain Injuries by the total number of cyclists, making the comparison of total TBIs for cyclists being 1.4x more than TBIs for pedestrians useless because there are more peds than cyclists.

If that's what you're saying, you didn't read the actual study before posting! In the second paragraph of the abstract for the 2006 french study, they clearly state "The annual incidence and mortality of severe TBI were 6.4 PER 100,000 (95% CI = 4.7–8.8) for un-helmeted cyclists"

The important part being: PER 100,000. Making your counter-argument invalid.

[jrockway]

"PER 100,000" doesn't cover the number of hours spent performing each activity.

[Jemaclus]

Per 100,000 what? Per 100,000 people in the general population? Per 100,000 un-helmeted cyclists? Per 100,000 cyclists in general?

[leeoniya]

i remember hearing on the news that "Most motorcycle accidents happen to those without a motorcycle-endorsed license."

of course this statistic is meaningless without knowing what ratio of endorsed:un-endorsed are actually on the road.

oh, and: http://www.horace.org/blog/wp-content/uploads/2012/05/How-to...

[anigbrowl]

Maybe...I've met a lot of people who drive everywhere, and cycling is a lot more popular in France than in the US. I went to read the study but I'm not going to pay $42 or sign up to rent it, so we can only speculate about the frequency of different transit modes in this study, what they controlled for, etc..