Motostats 2009

[DataDan]

As I have in past years, I'm going to summarize in a BARF thread the annual motorcycle crash data from various sources as it becomes available. I'll be starting with data from the US Department of Transportation, which today published its database of traffic fatality data for 2009.

The 2009 data shows a sharp drop in all traffic deaths, motorcycles included, which is good news, of course. But rather than reflecting sudden enlightenment of the driving/riding population to highway skills, it is probably a consequence of reduced vehicle use due to economic conditions. In future years it will be interesting to look back at data in this thread to see if it foreshadowed a longer term improvement in motorcycle safety or was just a momentary blip.

This year I intend to cover subjects similar to those I covered in Motostats 2006--US data on deaths, age distribution, helmet use, etc.--as well as certain local topics. If there is a subject you'd like to see covered, post up your suggestion or send me a PM.


Ever since the dramatic rebound in motorcycling from its early 1990s slump, crashes and deaths have steadily increased. In part, that's the inevitable result of a doubling of the number of registered bikes between 1997 and 2008. More riders, more crashes. Since the all-time low fatality count and rate of 1997, deaths have grown on average nearly 9% a year. But more than that, total deaths increased by 150%, and the fatality rate per registered motorcycle increased by 24%. So not only is the growing casualty count due to a growing motorcycle population, it's also due to greater average risk in the riding population.

In 2009, however, the trend reversed sharply. US annual deaths dropped to 4462 from 5312 in 2008, California deaths to 394 from 560, and Bay Area deaths to 59 from 95 (including the 9 counties on the Bay + Santa Cruz).


edit 2/23/11: I've updated the US and CA charts to include 2009 registrations and rates. Registrations by county for 2009 won't be available until later in the year. I'll update the Bay Area chart when they are.

edit 7/7/11: Bay Area chart updated.

 

[garciawork]

I'll be curious to find out age and helmet correlation when you get there.

 

[VicTim]

Thanks for your good work Dan. :thumbup

 

[DataDan]

Bay Area Fatal Crashes by Type, 2005-2009

One purpose of the Motostats threads is to help you understand how crashes do happen--so they don't happen to you. Here we're going to look at the breakdown by crash type for all Bay Area motorcycle fatalities 2005-2009. Included are nearly 400 deaths in the 9 counties on the Bay plus Santa Cruz County. This chart shows how those crashes occurred.

If you've followed previous Motostats threads, you may remember that running wide in a curve is the most common fatal motorcycle crash. This compilation confirms that. One in three riders killed in the Bay Area dies by running wide in a curve and hitting either a fixed object or an oncoming vehicle. Most are on our favorite mountain roads, but some are on freeway ramps and others are on curves in suburban areas.

One in five rider deaths is caused by loss of control on a straight roadway resulting in impact with another vehicle or a fixed object. These are kind of hard to understand in a general way--what's so hard about riding in a straight line? Combing through the details reveals a variety of factors. High BAC, extreme speed, stunts, wheel lockup under braking, and inattention to traffic all contribute.

Another one in five fatalities is due to a collision with a crossing vehicle. Some are oncoming left turners, others are vehicles on cross streets or pulling into the roadway from a driveway. Half of these are caused by a driver who failed to yield, but 40% are caused by the rider (in the remaining 10% the available evidence is ambiguous). The motorcyclist can contribute with excessive speed, running a stop sign or red light, or by himself turning left in front of an oncoming vehicle.

The remaining 25% or so of fatal crashes fall into a dozen different categories. In 7% the motorcyclist rear-ends another vehicle (though in less than 1% is the motorcycle rear-ended by another vehicle). In 4% a pass goes wrong. Usually that means a vehicle being passed turns when the motorcycle is alongside (on either the left or right). But in others, the motorcyclist pulls out to pass and collides with an oncoming vehicle. And another 4% occur when the rider is splitting lanes. In most of the lane-splitting crashes, the motorcycle somehow contacts a large truck, falls, and is hit by the truck or other vehicles.


An important message in the data is that many crashes happen in ways the rider didn't perceive as particularly dangerous at the time. For example, think about running wide in a curve. It has happened to me, and it has probably happened to you too. At speed that's a bit excessive, you lose focus and panic a little, then run wide, either across the fogline to the right shoulder or across the centerline into the oncoming lane. Most of the time you get straightened out and go on your way, maybe with a little self-criticism for the error. But if circumstances differ only slightly and in a completely random way, things can go to hell in a hurry. If there's no shoulder, just a guardrail, or if there's an oncoming SUV heading toward you at that precise moment, the non-event can become a serious crash.

There are easy lessons here: Don't ride through town at 75mph in a 25 zone with a half-dozen martinis in your tank. But there are harder ones too. Those are about the potentially deadly consequences of mistakes you may not have previously considered serious.

 

[RRrider]

In 7% the motorcyclist rear-ends another vehicle (though in less than 1% is the motorcycle rear-ended by another vehicle).

And another 4% occur when the rider is splitting lanes. In most of the lane-splitting crashes, the motorcycle somehow contacts a large truck, falls, and is hit by the truck or other vehicles.

Having recently read some threads on lane sharing, and the often cited fear of being rear ended as a justification to keep it from becoming illegal, I was surprised (and a little bummed) to see these data points. I really like CA's lane sharing policy and would prefer if the data more strongly supported the practice.

And let me add my thx, data dan, this is awesome. :thumbup

 

[DataDan]

Having recently read some threads on lane sharing, and the often cited fear of being rear ended as a justification to keep it from becoming illegal, I was surprised (and a little bummed) to see these data points. I really like CA's lane sharing policy and would prefer if the data more strongly supported the practice.

While the data highlights the danger of lane splitting, it also reveals the benefit in crashes that didn't happen. Riders here are seldom victims of rear-enders.

In the Bay Area 2005-2009, 27 riders were killed when they rear-ended other vehicles, but only 3 died when another vehicle rear-ended them. The 3 drivers involved in the latter were all drunk, and the crashes did not occur in situations where the rider could have been splitting. In two, the motorcycle was rear-ended on a freeway at high speed in early AM hours, and in the third the rider was slowing for a signal when hit. IMHO, the crash data supports very well the argument that lane splitting helps us avoid getting ass-packed in traffic.

The other side of the coin is the danger seen in deaths that occur while splitting. As I said earlier, most of these involve large trucks. Wide vehicles--especially in narrow lanes, such as the 238/580 construction where 4 riders were killed--pose a risk for lane splitters that isn't often discussed. We need to do a better job preparing noobs for lane splitting by showing them where the threats are. It isn't enough to offer the usual advice: between the #1 and #2 lanes only, speed delta of 10mph, no faster than 45mph (or whatever the rules of thumb are nowadays). They must also understand what the specific crash risks are and how to avoid them.

 

[budman]

Thanks DD...awesome as always.

I am glad there is a downward trend, but that trend could be doubled if we eliminated doing it to ourselves. Looking at our accidents plenty involve just us and our decisions/skill set/sobriety..etc.

If we as motorcyclist are better at what we do...we have a better chance of doing it again in 2012.

So...
Good decisions, training, repetition, practice, increased awareness...not being stupid has a huge impact on our making it home safe.

Lane sharing is certainly a hot topic in California and having Dan have a serious look at it is gold for me.

Dan..really you rock. Thanks for caring so deeply.

Dan knows..statistically if you present the stats people become more aware and you affect those stats in a positive way. ort

 

[RRrider]

While the data highlights the danger of lane splitting, it also reveals the benefit in crashes that didn't happen. Riders here are seldom victims of rear-enders.

In the Bay Area 2005-2009, 27 riders were killed when they rear-ended other vehicles, but only 3 died when another vehicle rear-ended them. The 3 drivers involved in the latter were all drunk, and the crashes did not occur in situations where the rider could have been splitting. In two, the motorcycle was rear-ended on a freeway at high speed in early AM hours, and in the third the rider was slowing for a signal when hit. IMHO, the crash data supports very well the argument that lane splitting helps us avoid getting ass-packed in traffic.

The other side of the coin is the danger seen in deaths that occur while splitting. As I said earlier, most of these involve large trucks. Wide vehicles--especially in narrow lanes, such as the 238/580 construction where 4 riders were killed--pose a risk for lane splitters that isn't often discussed. We need to do a better job preparing noobs for lane splitting by showing them where the threats are. It isn't enough to offer the usual advice: between the #1 and #2 lanes only, speed delta of 10mph, no faster than 45mph (or whatever the rules of thumb are nowadays). They must also understand what the specific crash risks are and how to avoid them.

Thx Dan! Very good point. I follow and believe your logic. It would be great to have a comparison dataset from a region where lane sharing is not allowed where the percentage attributed to being rear ended was higher than here. That would rule out the conclusion that being asspacked simply isnt a risk irrespective of lanesharing. Even better would be if the rear end percentage exceeded the lane sharing percentage + 1 which would suggest the lane sharing risk is less than the being rear ended risk. Does this exist? I know data on MC crashes isn't what we'd like. Nonetheless, if it existed, it would help us convince those not predisposed to this conclusion, like the sacbee reporter of a few weeks back.

 

[DataDan]

It would be great to have a comparison dataset from a region where lane sharing is not allowed where the percentage attributed to being rear ended was higher than here. That would rule out the conclusion that being asspacked simply isnt a risk irrespective of lanesharing.

I have done several comparisons between California and Florida for that purpose. I chose FL because it's the #2 motorcycling state in the US and it has a lot of urban/suburban traffic environments, where absence of lane splitting would seem to put motorcyclists at greater risk of being the victim in a rear-ender. Here is one data point:

Over the period 2004-2008, 46 California riders were killed in multiple-vehicle crashes when hit from behind, 1.9% of all motorcyclist deaths in the state. At the same time, 82 Florida riders were killed in that kind of crash, 3.2% of the total.​

But that is only suggestive because other factors could contribute to the difference. Maybe the rear-ender is a more common crash type among all vehicles in FL than in CA. And it doesn't get into details like my analysis in this thread of Bay Area crashes. Did those rear-enders in FL occur in situations where splitting could have prevented a crash?

Even better would be if the rear end percentage exceeded the lane sharing percentage + 1 which would suggest the lane sharing risk is less than the being rear ended risk. Does this exist? I know data on MC crashes isn't what we'd like. Nonetheless, if it existed, it would help us convince those not predisposed to this conclusion, like the sacbee reporter of a few weeks back.

There is no official source of lane-splitting crash data, so statewide analysis isn't possible. I know about it in the Bay Area from news reports (info for which comes from CHP and other LE agencies). A state project currently underway will make more data available for motorcycle crashes, including lane-splitting. So that kind of analysis will be possible in the future.

 

[RRrider]

Cool! Thx DD. Florida results are encouraging. Still if you add up the rear end and the lane sharing numbers, they are more than the Florida rear end numbers (lane sharing not allowed). That's the argument we'll need to ward off when lane sharing comes under legal attack in the legislature....

Look fwd to new data. Really, really[\b] glad you're doing this! Thx

 

[iehawk]

Awesome reading material as always, Dan. Thank you. :thumbup

About the FL data since I heard they don't have helmet law; I was wondering how much of that would affect the end result in some accidents. Although I imagine it wouldn't be easy to calculate the numbers factoring it or not.

 

[DataDan]

Awesome reading material as always, Dan. Thank you. :thumbup

Glad you like it.

About the FL data since I heard they don't have helmet law; I was wondering how much of that would affect the end result in some accidents.

For that to be a factor, an unhelmeted crash when hit from behind would have to put a rider at greater risk for serious head injury than other kinds of unhelmeted crashes. I don't know of any evidence either way.

 

[Mike95060]

Thanks for the hard work Dan.

 

[NorCal Factory]

I was told that flying single engine airplanes as a private pilot is about as risky as MC riding. Pilots review statistical analysis at all of the conferences because it really can save lives. Safety focused Motorcyclists should too.

This information reinforced what to watch out for me.
I bet it will increase safety for everyone who reads it and maybe save lives.

Thanks for all the hard work Dan.:thumbup

 

[DataDan]

The Other Guy

Which other drivers pose the most risk to riders? Gotta be geezers, right?

Well, no. Nearly as many riders are killed in crashes with drivers under 25 as over 55. Yet there are more than twice as many drivers on the road over 55 than under 25. And more riders are killed in crashes with drivers 16 to 19 than with all drivers 70 and over.

Of course, since many multiple-vehicle crashes are caused by the rider, the age distribution of other drivers in motorcycle crashes is, to some extent, a random selection of other drivers on the road. But young drivers are involved far out of proportion with their presence on the road.

 

[Mingo09]

Today the national safety council released a bunch of statistics on the odds of dying, in the U.S., by various means. These are lifetime odds of dying, and according to the NSC, the odds of any American dying by motorcycle is one in 802.

http://www.nsc.org/news_resources/injury_and_death_statistics/pages/theoddsofdyingfrom.aspx

This sounds very high (especially since the press release states that “The odds of dying are statistical averages over the whole U.S. Population,” which suggests it would be much, much higher for Americans who actually ride motorcycles).

I then thought about DataDan's Motostats—which, though great, always leave unanswered the question of “what is the actual lifetime risk of death for a California motorcyclist?” Or better yet,“what is my lifetime risk of motodeath since I'm a motorcyclist who puts about 7000 miles a year on my bike.” But I imagine that latter one is too much to ask.

I'm weak in math, so I've probably misinterpreted the data, but based on Motostats 2009 the fatality rate for California riders is about 78 per 100,000 registered motorcycles. (Did I get this right?) If this is the case, the average risk of motodeath for a California rider is one in 1,282. (Did I get this right?) I wonder two things—first, is there a significant factor (other than my own behavior—alcohol use, training, gear, style of riding, etc) left out of this equation? For example are there many motodeaths on bikes that are not registered?

Secondly, I wonder how an annual death rate of 1/1282 translates into a 30-year riding career. Again, the statistics are not strong in me—but what I understand about this kind of annual statistic, is that it kind of stays the same when you go from annual to lifetime (for example, I've heard that the “this year” and “lifetime” chances of death by commercial airline crash aren't much different from each other) because there are always many individuals who either exit or enter the pool—in other words, there are always thousands of new noobs, and new unlicensed, perhaps overly brash, or drunk riders.
Is this correct?

In any case, what do you all make of the one in 802 death rate for all Americans? And can anyone comment on the correctness of my interpretations of DataDan's numbers?

For the record, I know riding is crazy-dangerous. I also know that I can't accurately find my own risk of death from wide-scale statistics. But I would like to be able to say to parents and friends who fear for my life that a California motorcyclist’s risk of death is …......., with some confidence. Anyone willing to state (with statistical support) a number? DataDan?

 

[DataDan]

Today the national safety council released a bunch of statistics on the odds of dying, in the U.S., by various means. These are lifetime odds of dying, and according to the NSC, the odds of any American dying by motorcycle is one in 802.

This sounds very high (especially since the press release states that “The odds of dying are statistical averages over the whole U.S. Population,” which suggests it would be much, much higher for Americans who actually ride motorcycles).

I would have thought that the calculation was simply motorcycle deaths in a year / total deaths = 1/802. But for 2006 (date of the NSC estimates), there were roughly 4800 on-road motorcycle deaths and 2,400,000 total US deaths = 1/500. Using multiple years going back to the 1990s (when US motorcycle deaths were much lower than today), the rate I calculate is very close to the NSC's.

I then thought about DataDan's Motostats—which, though great, always leave unanswered the question of “what is the actual lifetime risk of death for a California motorcyclist?” Or better yet,“what is my lifetime risk of motodeath since I'm a motorcyclist who puts about 7000 miles a year on my bike.” But I imagine that latter one is too much to ask.

I'm weak in math, so I've probably misinterpreted the data, but based on Motostats 2009 the fatality rate for California riders is about 78 per 100,000 registered motorcycles. (Did I get this right?) If this is the case, the average risk of motodeath for a California rider is one in 1,282. (Did I get this right?) I wonder two things—first, is there a significant factor (other than my own behavior—alcohol use, training, gear, style of riding, etc) left out of this equation? For example are there many motodeaths on bikes that are not registered?

Registrations for 2009 aren't yet available, so the most recent rate in the chart in the OP is for 2008: 74 deaths / 100,000 registrations or 1/1353.

The problem with using the rate calculated for the overall riding population to draw an inference about individual risk is that we really don't know whether you're an "average" rider in ways that are important. Most of us feel strongly that riding sober, getting trained, wearing proper protective gear, adopting a safety-conscious attitude, and gaining experience will protect us. And we believe that we are safer than the "average" rider to the extent that he does not do the same. But there is no data to support those views (except about experience--one of the few strong results from crash risk studies).

Secondly, I wonder how an annual death rate of 1/1282 translates into a 30-year riding career. Again, the statistics are not strong in me—but what I understand about this kind of annual statistic, is that it kind of stays the same when you go from annual to lifetime (for example, I've heard that the “this year” and “lifetime” chances of death by commercial airline crash aren't much different from each other) because there are always many individuals who either exit or enter the pool—in other words, there are always thousands of new noobs, and new unlicensed, perhaps overly brash, or drunk riders.
Is this correct?

Using 1/1353, that's an annual probability of .0007391. The probability calculation of dying over a 30-year career using that annual probability is:

p(30) = 1 - (1 - .0007391)^30 = .022​

Or about 1 in 45. But that doesn't take into account any "experience" effects that might reduce annual probability as years accumulate.

For the record, I know riding is crazy-dangerous. I also know that I can't accurately find my own risk of death from wide-scale statistics. But I would like to be able to say to parents and friends who fear for my life that a California motorcyclist’s risk of death is …......., with some confidence. Anyone willing to state (with statistical support) a number? DataDan?

I'm not biting. :laughing

All we know is that 60-70 California riders die each year for every 100,000 registered motorcycles, and that's been true for the past 8 years or so. For the Bay Area, the rate is quite a bit lower, but we're not sure why that might be. Possible reasons are seasonality compared to the more populous LA area and more motorcycles owned per rider than other parts of the state.

To evaluate your own prospects--and to help assure others--I would suggest a qualitative analysis including the attitudes and traits discussed in this post

 

[RRrider]

Interesting. Either way, if I see the driver is young or old, I give a wide berth. Both scare me just for different reasons. But I guess this says, be more scared of the crazy invincible kids.

 

[Mingo09]

Thanks Dan.

That’s pretty ugly. It looks like I was wrong on two points:

(1) I didn’t consider that many riders register multiple bikes, and that, therefore, the death rate per rider is much higher than my initial estimation of 1/1282 (or your correction of my number: 1/1353). I presume there isn’t any published rate of ownership—a number that would allow us to generate a statistic per rider, rather than per number of bikes.


(2) I am evidently wrong about the fact that a statistic of 1/x in a shifting pool is roughly the same for one year as it is for multiple years. I don’t understand your math at all, but I assume it’s correct.

In any case, the number (for 30 years) is probably closer to 1/30 (assuming a lot of riders have multiple registrations). This won’t help in those “it’s not as bad as you think it is” conversations.

Are there perhaps any other factors I’m leaving out here? Are, for example, a sizable number of deaths recorded on unregistered bikes--or off road?

Thanks for the link to the 2005 post—good points, all.

So, about one in 30 of us (controlling for nothing) will die for the love of riding. I wish there were something equivalent in joy and thrill but less likely to take me out.

 

[DataDan]

(2) I am evidently wrong about the fact that a statistic of 1/x in a shifting pool is roughly the same for one year as it is for multiple years. I don’t understand your math at all, but I assume it’s correct.

I'm trying to resist being drawn into a quantitative discussion because I don't think it will answer your question in a useful way. However, if annual risk drops by half after 5 years or riding (a conservative estimate based on Hurt and MAIDS), the 30-year probability of death drops by approximately half too. So the benefit due to experience you mentioned in your previous post is real. I was just too lazy to include it in my calculation.

Are there perhaps any other factors I’m leaving out here? Are, for example, a sizable number of deaths recorded on unregistered bikes?

Yes indeed. Among California motorcyclists who died 2005-2009, 27% were on motorcycles either unregistered or registered to someone else, 25% of riders who had their BAC reported (80% did) were .08 or higher, and 9% were not wearing helmets. Of course, there's some overlap: Drunk and unhelmeted, a guy gets on his roommate's bike to show off his madd wheelie skillz and ends up in all three categories. But even after eliminating the bonehead antics that contribute to crashes, a substantial number remain where the rider didn't make any glaring mistakes.


You are not going to make yourself comfortable with riding risk by contriving a soothing probability. You will do it with experience. Every skill you master, every situation you encounter, every problem you solve, every tactic you devise will ease uncertainty. You will come to recognize specific endemic risks and gain confidence in your ability to reduce them to a tolerable level as you roll up the miles and learn the little lessons delivered on every ride.