IN HONEST STATISTICS (NOT THE KRYGOWSKI KIND), IS CYCLING SAFE — OR DANGEROUS?

Is cycling safe? Is cycling dangerous?

Answer: it depends where you view it from, and how skilled you are with statistical interpretation. This year the final tally in the USA will come to around 700 cyclists killed and about 40,000 motor passenger casualties.

Here are two ways of looking at it, with very different answers:

A cyclist is 2.9 times more likely to be killed on any journey than
someone riding in a car.
( http://www.ta.org.br/site/Banco/7man...PIpuchertq.pdf )

A cyclist is 11 times more likely to be killed per mile of travel than
someone riding in a car.
(ibid)

Can these widely divergent numbers be reconciled? Though their truth is guaranteed, are they actually the most meaningful numbers one can mine from the statistics?

HERE IS A LONGER PIECE THAT I FIRST PUBLISHED IN 2010 IF ANYONE WANTS TO DEAL IN PROVABLE FACTS RATHER THAN POMPOUS OPINION FROM WANNABE POLITICIANS.

S CYCLING SAFE?
by Andre Jute
Cycling statistics are thrown about by passionate advocates for this
or against the other with gay abandon for meaning and sense, so I
decided to conduct my own investigation and get at the facts.
Statistics is the art of spiraling in on enough sets of numbers in
broad agreement to make an informed decision. Decimals are a luxury
for ivory tower lurkers who wouldn't survive a day in the real world;
all that is required is a set of mutually reinforcing numbers tending
the same way.

Safety numbers do not stand in isolation. They are always in relation
to something else, which sets a baseline. In bicycle safety, the
comparison is with fatalities in automobile travel. It is not
necessarily the best comparison. For instance, if I were killed on the
road, my family would find it inconvenient but I would no longer care;
I would find being maimed or hurt on the road much more inconvenient,
but I have no good numbers for serious injury short of fatality. We
have to compare cycling to what we have, which is automobile
fatalities.

So one's entire attitude to bicycle safety depends on whether one
considers automobile travel safe enough. Most of us do. The unspoken
qualification is "in the light of its benefits." Bicycling must be
given the same benefit of weighing not just danger but net gain.

***

A cyclist is 2.9 times more likely to be killed on any journey than
someone riding in a car.
( http://www.ta.org.br/site/Banco/7man...PIpuchertq.pdf )

A cyclist is 11 times more likely to be killed per mile of travel than
someone riding in a car.
(ibid)

We know that cars travel faster than cyclists, and that people who
ride in cars travel further (14,400 miles for Americans according to
the DoT 2000/2001 transport census) than almost all bicyclists. So a
comparison per mile is not as indicative as first seems; in practice
it will be swamped by other factors. A more meaningfully direct
comparison is the risk per hour on the bicycle. We know from
experience that cars, depending on circumstances, travel 3 or 4 or 5
times as fast as bicycles. So we can calculate that:

A cyclist is roughly 2 or 3 or 4 times (11 divided by 3, 4, and 5,
and remember what I said about decimals) as likely to be killed per
hour on his bike as someone riding in an automobile. That accords well
with a number we already have, that a cyclist is 2.9 times as likely
to be killed per journey as a motorist.

All these numbers, including the outlyer of 11 times more cycling
fatalities per journey for cyclists than motorists, accord well with
the knowledge that most travel fatalities happen within three miles of
home, and the additional fact that most bicycles journeys are of less
than two miles.

We've now arrived at where cycling carries somewhere around three
times the risk of dying compared to motoring, with a fifty per cent
margin each way. It's extremely encouraging for a first approximation
to be so close, because not all cyclists ride under the same
circumstances or in the same way.

***

Let's check the numbers we have against known statistics. In the US,
about 700 cyclists and around 40,000 motorised travellers will become
traffic fatalities this year.

Nobody knows precisely how many cyclists there are but BRAIN reported
for the National Sporting Goods Association in 2008 that 44.7m rode
six or more times a year, of which 25m rode more than 24 times a year.
It is this 25m more or less regular cyclists we want to work with;
they very likely largely overlap the 24m who reported to the BTS in
2000-2001 that they cycled at least once a week. (
http://www.bts.gov/publications/high...table_a01.html
)

That works out to about 1 chance in 36,000 that a cyclist will be
killed on the road this year.

Nobody knows precisely how many people travel in internal combustion
vehicles either. But about 200m Americans have driving licenses, and
only 8 per cent of households don't have a car available; most of
those presumably travel by bus. We can probably safely say that around
390m Americans account for the 40,000 passenger casualties every year.
(That probably overstates the numbers who don't travel at all and take
trains, but it makes minuscule differences.)

That works out to about 1 chance in 9750 that an automobile traveller
will be killed on the road this year.

Eh? One chance in 36,000 that a cyclist will be killed v. one chance
in 9750 that a motorist will be killed this year. Can cycling really
be near enough four times safer than motoring? Even when we have
already decided that per trip and per hour cycling is about three
times more likely to get you killed than motoring?

Absolutely. Cyclists don't ride the enormous mileages motorists cover,
nor do they take as many trips. The per trip and per mile and per hour
disadvantage soon disappears over the longer term. I suspect that the
half-million or so habitual commuters in the States are pushing their
luck but recreational cyclists are exposed too little to worry (as
long as they don't do anything stupid, of course).

***

These numbers all refer to the States, where the average household has
1.8 cars for 1.7 licensed drivers, with consequences that are obvious.
I should however be surprised to discover that the numbers for any
anglophone country is drastically lower; they all aspire to emulate
the American lifestyle.

In my own country, Ireland, 9 cyclists were killed on the roads in
2006, the last year for which I have statistics, but that merely
reflects the drastic fall in cycling (never very popular) because most
people consider the roads far too dangerous; almost no children cycle
now. 29 pedestrians and 226 motorists also died on the roads, out of a
population of less than 4.5m; a motorist has about a 1 in 20,000
chance of dying in his or her car in any year, which sounds better
than in the States but the roads are much narrower and more crowded, a
nightmare for cyclists; I mention this to stress that gross numbers,
especially from foreign parts, should be adopted only with some
sensitivity to local conditions.

The bicycling cultures of Germany and The Netherlands have much lower
cycling fatalities on any sensible measure than anyone else but these
arise not so much from superior facilities as from a bicycle-directed
culture rather than an automobile-centred culture.

***
We're back where we started. A cyclist is more like to die on the road
than a motorist by a factor of 2.9 per trip, 11 per kilometre
(probably a not overly relevant statistic, as explained above), and
about 3 per hour on the bike.

I conclude that, roughly speaking, cycling carries in microcosm, ride
by ride, three times more risk of dying on the road than motoring.

However, in total, because cycling trips are shorter than motoring
trips, and there are fewer of them, the total macrorisk of death while
cycling is between three and four times *less*, on average over the
full year, than while motoring.

***

Commuters or other cyclists who ride big mileages are of course at
bigger risk and should consider the risk per hour on the bike, which
ranges from about 2-4 times that of driving (for traffic travelling no
faster than four times the cyclist's speed).

***

I cycle for my health. It works.

There are general health benefits to individuals, the environment and
society from cycling.

Everyone must make up his own mind. But I decided long ago that the
health benefits of cycling outweigh the per hour/per trip risks. I've
given up the car.

Andre Jute
10 April 2010.

***
Not copyright. May be freely reproduced. It would be a courtesy to use
the article in full including this note.

In Australia, even prior to the mandatory use of bicycle helmets, motor
vehicle drivers and bicycle riders were subject to the same risk of 0.84
fatalities per million trips, and similar risk on a per hour basis. Per
kilometer riders are 4 times more likely to die.

I don't think the fatality risk has changed _much_ since 1985-86. I
also have no idea how accurate the numbers are.

See Appendix A.
http://www.atsb.gov.au/media/36229/c...omparisons.pdf

--
JS

On 25/11/13 13:28, Andre Jute wrote:
Is cycling safe? Is cycling dangerous?

Answer: it depends where you view it from, and how skilled you are with statistical interpretation. This year the final tally in the USA will come to around 700 cyclists killed and about 40,000 motor passenger casualties.

Here are two ways of looking at it, with very different answers:

A cyclist is 2.9 times more likely to be killed on any journey than
someone riding in a car.
( http://www.ta.org.br/site/Banco/7man...PIpuchertq.pdf )

A cyclist is 11 times more likely to be killed per mile of travel than
someone riding in a car.
(ibid)

Can these widely divergent numbers be reconciled? Though their truth is guaranteed, are they actually the most meaningful numbers one can mine from the statistics?

HERE IS A LONGER PIECE THAT I FIRST PUBLISHED IN 2010 IF ANYONE WANTS TO DEAL IN PROVABLE FACTS RATHER THAN POMPOUS OPINION FROM WANNABE POLITICIANS.

S CYCLING SAFE?
by Andre Jute
Cycling statistics are thrown about by passionate advocates for this
or against the other with gay abandon for meaning and sense, so I
decided to conduct my own investigation and get at the facts.
Statistics is the art of spiraling in on enough sets of numbers in
broad agreement to make an informed decision. Decimals are a luxury
for ivory tower lurkers who wouldn't survive a day in the real world;
all that is required is a set of mutually reinforcing numbers tending
the same way.

Safety numbers do not stand in isolation. They are always in relation
to something else, which sets a baseline. In bicycle safety, the
comparison is with fatalities in automobile travel. It is not
necessarily the best comparison. For instance, if I were killed on the
road, my family would find it inconvenient but I would no longer care;
I would find being maimed or hurt on the road much more inconvenient,
but I have no good numbers for serious injury short of fatality. We
have to compare cycling to what we have, which is automobile
fatalities.

So one's entire attitude to bicycle safety depends on whether one
considers automobile travel safe enough. Most of us do. The unspoken
qualification is "in the light of its benefits." Bicycling must be
given the same benefit of weighing not just danger but net gain.

***

A cyclist is 2.9 times more likely to be killed on any journey than
someone riding in a car.
( http://www.ta.org.br/site/Banco/7man...PIpuchertq.pdf )

A cyclist is 11 times more likely to be killed per mile of travel than
someone riding in a car.
(ibid)

We know that cars travel faster than cyclists, and that people who
ride in cars travel further (14,400 miles for Americans according to
the DoT 2000/2001 transport census) than almost all bicyclists. So a
comparison per mile is not as indicative as first seems; in practice
it will be swamped by other factors. A more meaningfully direct
comparison is the risk per hour on the bicycle. We know from
experience that cars, depending on circumstances, travel 3 or 4 or 5
times as fast as bicycles. So we can calculate that:

A cyclist is roughly 2 or 3 or 4 times (11 divided by 3, 4, and 5,
and remember what I said about decimals) as likely to be killed per
hour on his bike as someone riding in an automobile. That accords well
with a number we already have, that a cyclist is 2.9 times as likely
to be killed per journey as a motorist.

All these numbers, including the outlyer of 11 times more cycling
fatalities per journey for cyclists than motorists, accord well with
the knowledge that most travel fatalities happen within three miles of
home, and the additional fact that most bicycles journeys are of less
than two miles.

We've now arrived at where cycling carries somewhere around three
times the risk of dying compared to motoring, with a fifty per cent
margin each way. It's extremely encouraging for a first approximation
to be so close, because not all cyclists ride under the same
circumstances or in the same way.

***

Let's check the numbers we have against known statistics. In the US,
about 700 cyclists and around 40,000 motorised travellers will become
traffic fatalities this year.

Nobody knows precisely how many cyclists there are but BRAIN reported
for the National Sporting Goods Association in 2008 that 44.7m rode
six or more times a year, of which 25m rode more than 24 times a year.
It is this 25m more or less regular cyclists we want to work with;
they very likely largely overlap the 24m who reported to the BTS in
2000-2001 that they cycled at least once a week. (
http://www.bts.gov/publications/high...table_a01.html
)

That works out to about 1 chance in 36,000 that a cyclist will be
killed on the road this year.

Nobody knows precisely how many people travel in internal combustion
vehicles either. But about 200m Americans have driving licenses, and
only 8 per cent of households don't have a car available; most of
those presumably travel by bus. We can probably safely say that around
390m Americans account for the 40,000 passenger casualties every year.
(That probably overstates the numbers who don't travel at all and take
trains, but it makes minuscule differences.)

That works out to about 1 chance in 9750 that an automobile traveller
will be killed on the road this year.

Eh? One chance in 36,000 that a cyclist will be killed v. one chance
in 9750 that a motorist will be killed this year. Can cycling really
be near enough four times safer than motoring? Even when we have
already decided that per trip and per hour cycling is about three
times more likely to get you killed than motoring?

Absolutely. Cyclists don't ride the enormous mileages motorists cover,
nor do they take as many trips. The per trip and per mile and per hour
disadvantage soon disappears over the longer term. I suspect that the
half-million or so habitual commuters in the States are pushing their
luck but recreational cyclists are exposed too little to worry (as
long as they don't do anything stupid, of course).

***

These numbers all refer to the States, where the average household has
1.8 cars for 1.7 licensed drivers, with consequences that are obvious.
I should however be surprised to discover that the numbers for any
anglophone country is drastically lower; they all aspire to emulate
the American lifestyle.

In my own country, Ireland, 9 cyclists were killed on the roads in
2006, the last year for which I have statistics, but that merely
reflects the drastic fall in cycling (never very popular) because most
people consider the roads far too dangerous; almost no children cycle
now. 29 pedestrians and 226 motorists also died on the roads, out of a
population of less than 4.5m; a motorist has about a 1 in 20,000
chance of dying in his or her car in any year, which sounds better
than in the States but the roads are much narrower and more crowded, a
nightmare for cyclists; I mention this to stress that gross numbers,
especially from foreign parts, should be adopted only with some
sensitivity to local conditions.

The bicycling cultures of Germany and The Netherlands have much lower
cycling fatalities on any sensible measure than anyone else but these
arise not so much from superior facilities as from a bicycle-directed
culture rather than an automobile-centred culture.

***
We're back where we started. A cyclist is more like to die on the road
than a motorist by a factor of 2.9 per trip, 11 per kilometre
(probably a not overly relevant statistic, as explained above), and
about 3 per hour on the bike.

I conclude that, roughly speaking, cycling carries in microcosm, ride
by ride, three times more risk of dying on the road than motoring.

However, in total, because cycling trips are shorter than motoring
trips, and there are fewer of them, the total macrorisk of death while
cycling is between three and four times *less*, on average over the
full year, than while motoring.

***

Commuters or other cyclists who ride big mileages are of course at
bigger risk and should consider the risk per hour on the bike, which
ranges from about 2-4 times that of driving (for traffic travelling no
faster than four times the cyclist's speed).

***

I cycle for my health. It works.

There are general health benefits to individuals, the environment and
society from cycling.

Everyone must make up his own mind. But I decided long ago that the
health benefits of cycling outweigh the per hour/per trip risks. I've
given up the car.

Andre Jute
10 April 2010.

***
Not copyright. May be freely reproduced. It would be a courtesy to use
the article in full including this note.

On 25/11/13 14:51, James wrote:
In Australia, even prior to the mandatory use of bicycle helmets, motor
vehicle drivers and bicycle riders were subject to the same risk of 0.84
fatalities per million trips, and similar risk on a per hour basis. Per
kilometer riders are 4 times more likely to die.

I don't think the fatality risk has changed _much_ since 1985-86. I
also have no idea how accurate the numbers are.

See Appendix A.
http://www.atsb.gov.au/media/36229/c...omparisons.pdf


Actually, I'll revise that. I think the fatality risk for motor car
drivers has dropped while the risk for bicycle riders has stayed the same.

I don't think helmets have actually saved many people's lives, and the
road toll seems to drop each year though our population is growing.

--
JS

On Sun, 24 Nov 2013 18:28:53 -0800 (PST), Andre Jute
wrote:

( http://www.ta.org.br/site/Banco/7man...PIpuchertq.pdf )

I should point out that this article was written in 2000 and uses data
from 1975 thru 1998. I suspect many things have changed in the last
20 years. For example, see Exhibit 12 on Pg 16. If one follows the
declining trend line of bicycling fatalities in various countries, it
should be near zero by today. Obviously it's not zero, making
extrapolations from such old data a rather dubious proposition.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Mon, 25 Nov 2013 15:30:31 +1100, James
wrote:

I think the fatality risk for motor car
drivers has dropped while the risk for bicycle riders has stayed the same.

In the USA, we're more efficient at killing bicyclists:
http://www-nrd.nhtsa.dot.gov/Pubs/811743.pdf
Note the increase in percentage of bicyclists fatalities from 2002
thru 2011 from 1.5% of all traffic fatalities, to 2.1%. I'm wondering
if this correlates with the increased use of motor powered bicycles.

Some interesting comments on the above data:
http://www.bicyclinginfo.org/facts/crash-facts.cfm

More numbers on when fatalities occur etc:
http://www.iihs.org/iihs/topics/t/pedestrians-and-bicyclists/fatalityfacts/bicycles/2011

I'm not worried. I'll probably die in a supermarket parking lot, run
over by someone who thinks all the rules of the road are suspended
while driving diagonally across the parking lot.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Monday, November 25, 2013 4:30:31 AM UTC, James wrote:
On 25/11/13 14:51, James wrote:

In Australia, even prior to the mandatory use of bicycle helmets, motor

vehicle drivers and bicycle riders were subject to the same risk of 0.84

fatalities per million trips, and similar risk on a per hour basis. Per

kilometer riders are 4 times more likely to die.



I don't think the fatality risk has changed _much_ since 1985-86. I

also have no idea how accurate the numbers are.

A cyclist being 4 times as likely to die per kilometer as the occupant of a car is broadly in accordance with the American numbers I worked with.

See Appendix A.

http://www.atsb.gov.au/media/36229/c...omparisons.pdf

Actually, I'll revise that. I think the fatality risk for motor car

drivers has dropped while the risk for bicycle riders has stayed the same..

I don't think helmets have actually saved many people's lives, and the

road toll seems to drop each year though our population is growing.

If the fatalities haven't kept pace with growing population, something is working. Whether it is helmets would require data and analysis. It could be anything, including even the roadworks you dislike. I made a crack at the hospital about what can be seen from the third floor of the bike lanes on the roads outside the hospital gates: "All cycle lanes lead straight to Accident & Emergency," and a guy who worked Resuscitation said, "To that extent, they've worked. We get the donors faster." (Anyone on a pedal- or motor-bike in medical slang is "a donor".)

Specifically on helmets, the New York whole universe compilation of serious cycling accidents that I discussed before, that anti-helmet zealots avoid so assiduously, is the best indicator that helmets do save lives. In it there was a clear trend for the helmet wearers to suffer a lower fatality rate..

Andre Jute

Andre Jute wrote:

snip
Let's check the numbers we have against known statistics. In the US,
about 700 cyclists and around 40,000 motorised travellers will become
traffic fatalities this year.

In NZ it's

Driver ~130
Passenger ~70
Motorcycle ~40
Pedestrian ~30
Pedal cycle ~10
Other ~5

With most fatalities being older people. We've got around 2.9 million
drivers and something like 0.75 million cyclists (with about half of those
regulars and under 10% competative). There's only around 75000 motored on
two wheels.

1/2000 motorbikers.
1/22000 drivers.
1/75000 cyclists.

Noting that almost all cyclists are also drivers, a cyclist is over
three times as likely to die in their car as on their pushbike. The
motorbike crowd is, meanwhile, around a dozen times more likely to die on
two wheels than four.

And realistically, we're just about all pedestrains, even babies get
pushed around in prams.

1/120000 pedestrians.

So, more likely to die on your bike than on foot, but not that bad.


One thing I found recently though, was that only ~30% of cyclists per
year on today's numbers are killed by being run over. Another ~20% are
judged at fault in a collision (riding illegally and ending up under a
truck, typically), and the remains are non-collision deaths like strokes and
heart-attacks while riding, or catching a tree on downhill adventures.



And per-hour or per-km it's worse, as ususal, but cyclists who do more
hours and more km are proportionately safer, so real numbers are pretty hard
to find or figure out in the first place.

Thanks, Andre, nice view of things.



Holy crap. The average driver here does ~200km/week. I nearly manage
that when it's summer time on the bike. Speaking of which, really must get a
new chain on the thing and get back into it.

--
tussock

On Sunday, November 24, 2013 11:30:31 PM UTC-5, James wrote:

Actually, I'll revise that. I think the fatality risk for motor car
drivers has dropped while the risk for bicycle riders has stayed the same..

I don't think helmets have actually saved many people's lives, and the
road toll seems to drop each year though our population is growing.

I think road death tolls change for various reasons, some of which are properly credited, some of which are not. For example:

Death tolls tend to rise or fall with road use. When hard times and/or gas prices and/or demographic trends reduce the miles driven, fewer drivers and passengers are killed. “Millennials aren’t driving cars,” some claim. OTOH, cycling seems to be rising in popularity, so bike deaths should have a tendency to rise, even though that tendency may be partially offset by other factors.

There have been marked engineering changes in cars. Aside from modern (explosively) inflatable car interiors, structural changes in car bodies do a better job of protecting occupants. We now see stability control common in newer cars. Lane departure warnings are popping up in some. (Of course, these may trigger some serious risk compensation; we'll see, I guess.)

There's pretty constant improvement in roadway design benefiting motorists. Although freeways are already far safer than ordinary streets, our state is spending money installing cable barriers in freeway medians, to make them safer yet. Newly re-decked bridges now have rain grooves (which are pretty exciting when I'm on my motorcycle). Turnpike toll booths have very elaborate impact barriers. And suburban roads are also being redesigned to smooth automobile travel and make it safer.

Unfortunately, those same pro-motorist road changes can certainly dissuade walking and biking, when crossing a street becomes a six lane sprint for an elderly man, or a new freeway means a half mile trip to a grocery is now a four mile bike ride to cross at the nearest over-freeway bridge. Things like that drive pedestrians and many bicyclists into their cars. It's really a net detriment, but those who simple-mindedly count only deaths, not rates, may claim this as a victory.

Changes in demographics work in other ways besides reducing driving. "White flight" and new suburbs in cornfields mean more and more city workers use expressways for larger portions of their commute. Again, those are far safer than city streets.

One that I believe is very important, but only rarely credited, is that emergency medical equipment and techniques have gotten markedly better. There's technology in ERs that never existed before. And physicians really do know a lot more now than even 20 years ago.

What I'd love to see would be more competence and courtesy from all road users - motorists, bicyclists, pedestrians - because of public information campaigns and other education efforts. Sadly, I think that's a negligible contribution to the improvements we've seen.

- Frank Krygowski

A couple of points on reading all the above.
The Australian accident statistics improvement must be in large part due to the cracking down on drink-driving in that country.
I hae me doots about the relative risk of cycling v. driving. I've known in my life three people killed in car crashes and I've known seven killed off bikes. In addition, the last time (I've done it twice) I cycled Lands End to John O'Groats, one day at coffee four of us were chatting and each one of us had been struck by a car and injured while cycling (we were all in our early sixties).
I feel that cycling would be safer if there was an apparatus in a car which rendered the use of a phone impossible while driving. They are undoubtedly a menace.

On Monday, November 25, 2013 12:37:29 PM UTC-5, Garry Lee wrote:
A couple of points on reading all the above.

The Australian accident statistics improvement must be in large part due to the cracking down on drink-driving in that country.

In my rather long post above listing some causes of increased road safety, I'd intended to mention the big campaigns against drunk driving, but I lost track of it.

I should also have mention speed enforcement and red light cameras, although they're unpopular (since people apparently feel they have a constitutional right to speed and run red lights). One cycling advocate I know well said she was against such cameras. Then she came across data for her city which showed that the intersections where they were installed had _tremendous_ drops in crashes.

I feel that cycling would be safer if there was an apparatus in a car which rendered the use of a phone impossible while driving. They are undoubtedly a menace.

I've longed for a device to jam all cell signals within a couple hundred feet of me when I'm on the road. Preferably with a loud, loud blast of sound into the ear of the offender!

- Frank Krygowski