IS CYCLING SAFE? by Andre Jute

On Friday, June 5, 2015 at 4:00:47 PM UTC-5, Andre Jute wrote:
IS 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...le_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 a 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.

Your research could be summed up in one sentence.

Because a bicycle has NO protection, cyclists are far more like to be killed when struck by a car.

If cyclists keep that in mind and drive as if motorists were out to run them over, they will have a good time and long life cycling. :-)

Andy

On Thursday, June 18, 2015 at 8:15:58 PM UTC+1, Andy K wrote:
On Friday, June 5, 2015 at 4:00:47 PM UTC-5, Andre Jute wrote:
IS 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...le_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 a 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.

Your research could be summed up in one sentence.

Because a bicycle has NO protection, cyclists are far more like to be killed when struck by a car.

If cyclists keep that in mind and drive as if motorists were out to run them over, they will have a good time and long life cycling. :-)

Andy

Can't go wrong being careful.

Andre Jute