You said it's wrong, "over and over again" so show a correction. The referenced under-reporting was addressed by using a range of values.

I think that you need to get specific if you want to credibly claim that someone is making mistakes in math.

To be specific about your question, https://www.nhtsa.gov/NASS "General Estimates System data come from a nationally representative sample of police reported motor vehicle crashes of all types, from minor to fatal. The system began in 1988, and was created to identify traffic safety problem areas, provide a basis for regulatory and consumer initiatives, and form the basis for cost and benefit analyses of traffic safety initiatives. The information is used to estimate how many crashes of different kinds take place, and what happens when they occur."

So my presumption about the source of the data appears to have some validity.

(incidentally, I did not use FARS data which applies to fatality rates, so your "hint" is misguided)

FARS and NASS have merged into GES.

To start.

"In order for a crash to be eligible for the GES sample a police accident report (PAR) must be completed, it must involve at least one motor vehicle traveling on a traffic way, and the result must be property damage, injury, or death."

Follow up things to consider. What is threshold of property damage value where a PAR must be completed? (Varies by jurisdiction.) What is the threshold of injury where a PAR must be completed? (Varies by jurisdiction.)

What is injury that rolls up into the report that you cited? (It excludes possible injury, and believe it or not a "momentary loss of consciousness" and "limps" are possible injuries.)

So, how much does that effect your numerator?

-mr. bill

And to give you something to pause and think about.

Under what circumstances does a fatal dooring get reported in GES?
Under what circumstances does an injury dooring get reported in GES?

-mr. bill

For a list of the data files https://www-nrd.nhtsa.dot.gov/Pubs/811853.pdf, and you will find the answer you seek.

It's clear that you have no credible objection to the math since you're scanning through the web sites looking for something to object to, but not enough to check your objections. It's not my intent to argue with you whether the National Highway Transportation Safety Agency knows what they're doing in gathering statistics. I've identified the sources of their data sufficiently to know that it's applicable.

The numerator, as you put it, is fine.

Highway traffic statistics involve road traffic. We haven't made any bones about that.

But, if you want to make sure that doorings are included at least once, feel free to multiply the number of accidents by 1.008 from the Cross-Fisher study. It won't change the answers given the low degree of precision.

To put it bluntly, you are very wrong there.

In very few states is the value of a totaled bicycle high enough to trigger a requirement for a PAR report, and the damage that a bicycle does to a car is unlikely to either.

Second, one of the *specific* injuries we are worried about, a loss of consciousnesses which might indicate a TBI, is not captured by the data. I don't know how you imagine that this number is not relevant.

Third, in a large number of jurisdictions, absent a triggering property loss, only if at least one injury is "severe" enough is there are requirement for a PAR. I don't know how you imagine that this number is not relevant.

Fourth, a significant number of bicycle crashes on the road don't involve motor vehicles, which is not captured by the data. I don't know how you imagine that this number is not relevant.

Fifth, a significant number of bicycle crashes don't take place on the road. Now, while you might decide that *you* are only worried about accidents that happen on the road, others might not agree.


You've presented your analysis as "worst case" numbers, yet you've dramatically UNDERSTATED the numerator. (We aren't talking by a few percent here.)
(That's before we even get to your overstating the denominator in your "worst case" estimate.)

-mr. bill

Have you even read the posts? We're not even talking about TBI or severity of the injuries in the accident data.

None of what you wrote here appears to be relevant, except for the vague claim that the traffic accident rate is dramatically understated. It doesn't even bother me that you don't even try to support it, because I'm not going to argue. Write a paper attacking the DOT NHSTA for drastically understating traffic accidents.

I don't have to write a paper.


-mr. bill

It's a list of references for some paper about ER stats? Of itself, that tells us literally nothing.

I avoided the hospital ER related data because of the well known problems of under-reporting and mis-reporting, and focused exclusively on traffic safety statistics. My calculations are with respect to traffic safety and injuries, using only data gathered by the federal DOT. DOT may use ER data, among a number of other sources some of which are listed in that first manual I linked you to, but I haven't drilled that far. I'm using DOT data, concerning traffic incidents. It does not pertain to mountain biking, or anything off-road.

An ER analysis is a different look at a different set of circumstances, for a different purpose. It does not confirm nor contradict me, unless someone sets up a related calculation with enough similarities to compare. Since my math is wrong over and over again, and you present the paper's references as your evidence that DOT/NHSTA data is "drastically understated", if falls upon you to supply a bit more justification other than "I don't have to write a paper". If you want to demonstrate something.

What conclusions are drawn from or by the authors of "Injuries to Pedestrians and Bicyclists: An Analysis Based on Hospital Emergency Department Data" about the probability that any cyclist will suffer any injury during a year, which would be or was mitigated or avoided by using a helmet? If there is such a conclusion that you can deliver to us, your belligerent style would be made worthwhile.

And you didn't even bother to glance at the title of the FIRST reference.

(TLDNR for you - it is well established that studies of health data compiled from police reports have limitations, because, uh, well, providing robust and reliable health data IS NOT A POLICE FUNCTION.)

-mr. bill

We're looking for data, conclusions, supported theories even. A title isn't of much use.

I think what mr_bill is saying is the same thing I brought up, what about all the people that had a crash and hit their heads but aren't counted in any statistics because it wasn't reported to anyone because the helmet worked good enough for them that they just dusted themselves off, and went on their way... Could be 10s of thousands of people in a year...

EDIT; That number will never be known, thus the helmet thread... If it could be known there would be no helmet thread, but since nobody can say XXX number of people were helped and they didn't go to the ER, we only know the XXX number of people it didn't help enough to keep them from the ER...

It's much worse than that. Even if you were lying unconscious on the side of the road after getting hit by a car, and even if the police responded and they found you unconscious, after you came to, if you locked up your busted bike and limped to your doctor's office or the ER and were treated for a concussion there still might not even be a PAR, and in the unlikely event there was a PAR you'd be coded "possible injury" which isn't counted in the roll up of injury data.

(And what I've learned from the SFW - everlasting gobstopper thread is if the folks who are sending everyone here on snipe hunts aren't even capable of NSFW - using google, then c'est la vie, not my problem man.)

-mr. bill

We addressed this, with the 80/20 proportion of helmeted/non-helmeted riders and supposing ALL of the injuries were non-helmeted there would be 4 times as many ... never mind, we're repeating things here.

Yes we did, and I agree, Talking about % is not the same as talking about actual numbers of people, saying 10,000 people crashed and 2,500 went to ER even tho wearing a helmet is not the same as saying 7,500 people didn't need to go to ER because they wore a helmet... (made up numbers). And yes we, have said it but the bare headers totally ignore the helped numbers as if there weren't any and just keep saying the injured numbers where the helmet failed...

EDIT; Lately they do say that a helmet can help a bit, scratches, bumps, but minor stuff only... At least now they have stopped saying a helmet actually increases the chance of injury, causes injuries, you are better off without a helmet...

What I am trying to say is, to me there is a huge difference in the importance of different angles/ways of looking at things, when trying to decide whether to wear a helmet or not, in other words is it worth it.?

Normal way of looking at it seems to be, well, it's a 1% chance of getting into an acident, and it's a 1% to 5% chance that a helmet would be needed if you do get into an acident, and people wearing helmets still end up in the ER so helmets don't work good enough anyways, so wearing a helmet is a waste...

My way of looking at it is what if one said, 10,000 people hit their head but 7,500 didn't go to the ER because a helmet helped but we don't hear about them...
Or maybe it was................................100,0000 people hit their head but 75,000 didn't go to the ER because a helmet helped but we don't hear about them...

So, the 7,500 ? people that the helmet may have helped, or maybe 75,000 ? or the (actual) unknown number? people helped by helmets is totally getting ignored/unheard, because we don't have any real provable numbers...


That's the way I see this helmet debate...

Or maybe 100,000 people hit their head, but 7,500 (or 75,000) didn't go to the ER because the injury was minimal or non-existent even though they didn't have a helmet on. Who knows...

We do have real numbers - just they are ignored in favor of swagging numbers.

Why? Because we are in a maze of twisty little passages, all alike.

-mr. bill

Exactly, because of this the helmet debate goes on and on...

And we could all decide to respect one another's choice, but where would the fun be in that, right?

Yes we could, and I do... I just want to put forward my way of looking at it for people making a choice, pointing out that helmets do help, and probably help more people than one thinks looking at the % where needed. It's just that helmets do have limitations too and that seems the main focus of the bare headers, totally ignoring/downplaying the benefits...


EDIT; Of course many people also say my helmet saved my life, which is probably doubtful...

Every now and then, things wind down here in Helmet Thread and stay quiet for a while until some new member or two come in and stir things up again. And it's usually not the Barehead Brigadiers who do this, it's usually a Helmeteer not respecting personal choice, one of the "organ donor" or "I guess your brain isn't worth even $30" or "A helmet saved my life -- you should wear one, too!" crew. And when confronted with resistance by the Bareheaders, the uninformed Helmeteers get all butt-hurt and start calling the Bareheaders "anti-helmet" when in fact, they are just defending their position in the face of evangelic Helmeteerism. Then these newbs usually rage-quit, with a quip or two against Bareheaders on the way out.

This sequence is as predictable as Helmet Threads are long...

Let me restate the fact that many people including me have first hand knowledge how a helmet prevented injury. OTOH the anti helmet types are operating on flawed studies, reports, hope, and random probabilitys. They operate on the idea that the probability of having a crash is remote. But OTOH due to probability they may crash on their next ride.

...as is the regular logic-challenged posts of rydabent.

I guess all the anecdotes of those who have ridden for years and not crashed, those who have crashed and not hit their heads, and those who have crashed and still sustained head injury even while wearing a helmet don't count? Because you are as quick to dismiss such claims as reasons for not wearing a helmet as you claim those who don't wear helmets dismiss your anecdotes as reason for wearing a helmet.

Really? I would like to see those numbers... Been here for years and never seen any numbers relating to how many injuries were mitigated by helmets... Only seen how many failed to save the person wearing one from injuries...

"Smoking is the leading preventable cause of death in the United States."

"Cigarette smoking causes more than 480,000 deaths each year in the United States. This is about one in five deaths." -CDC on Smoking and Death

Coincidentally, nearly 1 in 5 Americans smoke. -WebMD

^^There are some cold, hard facts in numerical form. Yet 20% of Americans STILL smoke. Really!!?? So what are the chances that given "those numbers" (if in fact "those numbers" even exist) that you or anyone else would start wearing a helmet to possibly, maybe, under prefect circumstances, preserve your health?

Around 2% of Americans ride bikes regularly. Riding a bike does not almost guarantee anyone a serious head injury like smoking compromises health in nearly everyone who partakes. So of that 2% of cyclists, at worst, the total number of serious head injuries must be miniscule compared to that 480,000 number for smokers. So my question is: Given cold, hard facts and numbers regarding serious head injuries resulting from cycling - WHO BLOODY CARES?

"Bicycle-related injuries account for approximately 900 deaths...annually [In the USofA]" -American Family Physician

Even if every one of those 900 deaths were a result of not wearing a helmet, the risk to the individual cyclist is miniscule.

Enjoy those numbers!