Safety in Numbers

"_" wrote in message
...
On Tue, 09 Sep 2008 13:05:20 +0100, Peter Clinch wrote:

_ wrote:

Cycling is not more dangerous than walking.

Given certain measures over certain populations it isn't, but it's a
too-sweeping statement not to benefit from further qualification.

I would suspect there could well be particular locations where cycling
is more dangerous than walking, and certain individuals for whom cycling
is more dangerous than walking.

Pete.

Extremes do not represent the norm.

and averages cannot be assumed to apply to individual cases.

"Mike Clark" wrote in message
.uk...
In message
Phil W Lee phil(at)lee-family(dot)me(dot)uk wrote:

Mike Clark considered Tue, 09 Sep 2008
12:52:39 +0100 the perfect time to write:

snip
but are we so confident in our models that we couldn't conceive of
getting an unexpected result?

As far as I can tell, the confidence is such that while we can't be
totally certain that a rise in cycling numbers will ALWAYS lead to an
improvement in safety (the numbers are sufficiently low that one
random event can skew figures for a year or longer), we can be very
confident that it is more effective than (for example) mandating
helmet use.

Ah but the cycle helmet example is a good one. The small scale case
controlled studies gave rise to results that when modelled gave a
prediction that great benefits would come from mandatory helmet use.
However when the experiment was carried out in several countries
(Australia, New Zealand and Canada) it was discovered that the results
didn't fit with the predictive models. So the conclusion is that the
models were wrong.


Out of interest, did these studies calculate any confidence intervals on
their predictions?

PK wrote:

Cycling on the road needs constant vigilance to remain safe - walking on
the pavment needs the same level of viginalce only when crossing the
road.

That is /vastly/ overstated: nobody would go bicycle touring for
pleasure if it required "constant vigilance"...

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

_ wrote:
On Tue, 09 Sep 2008 16:30:44 +0100, Peter Clinch wrote:

_ wrote:

Would the particulars of "any particular case" be a good reason for coming
to a conclusion about relative safety?
My point was, and remains, it's disingenuous to say "cycling is safer
than being a ped, period". And I say that because it's unsafe to assume
that on a public forum such as this it will apply to anyone you say it to.

The sweeping statement has not been qualified to say it's about relative
safety of a population sized group. It should be, even if all that's
done is insertion of "typically the case that". Go around talking in
absolutes and you just give people a good reason to think you're talking
****e, and that doesn't help anyone.


As opposed to talking about extremes, or the irrationallity of assuming
that the norm will predict any single instance?

What /are/ you on about?

My point was, and remains, it's disingenuous to say "cycling is safer
than being a ped, period".

Your point seems to be to pick holes in string vests and say "I told you
so", which is a bit, ummm, pointless.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

On 9 Sep, 12:15, David Martin wrote:
On Sep 9, 9:49*am, Toom Tabard wrote:
*When cycling safely

and considerately I constantly had near-misses which could easily have
had serious consequences. That rarely if ever happens when walking.

I have never heard of a near miss having serious consequences. A hit,
yes, but a miss, no.


That is no more than trite and vacuous sophistry

Many people over estimate the severity of a near miss (close pass). It
is unpleasant and annoying, but is rarely dangerous. Obviously the
margin for error is reduced, increasing the overall number of not
quite near misses, so it is worthwhile encouraging vehicles to leave
more space.


The number of near misses in different situations is a good indicator
of the probability of such a situation resulting in an actual event
with serious consequences.

And you are putting rather too literal an interpretation of my use of
'near miss', and redefining it as a close plass. To clarify, I'm using
it in the ordinary sense of all circumstance which which presented a
clear danger but did not develop into an actual accident.

It is indeed the case that you will have fewer close passes if you
'encourage vehicles to leave more space'. As a defensive cyclist/
driver/pedestrian, I do so. But again, you have far more control over
that as a pedestrian than as a cyclist actually mixing with vehicle
traffic, where your control of the situation is much more limited and
compromised by the action of others.

Toom

On 9 Sep, 12:44, _ wrote:
On Tue, 9 Sep 2008 01:49:41 -0700 (PDT), Toom Tabard wrote:
On 8 Sep, 12:27, "wafflycat" wrote:

Without fail, the number one reason folk give to me as to why they won't
cycle on roads is that it is "unsafe". Of course, those of us who do cycle
know that in the great scheme of things it is no more dangerous than walking
and a zillion other activities deemed as safe to do- Hide quoted text -

I walk in town, a lot more than and a lot further than the average
person. I no longer cycle in town, because I find it is unsafe, and it
certainly many times more hazardous than walking. When walking, you
only mix with traffic when crossing, and can freely choose, monitor
and control how you do that. When you are cycling and permanently
interacting with traffic you have no such control. When cycling safely
and considerately I constantly had near-misses which could easily have
had serious consequences. That rarely if ever happens when walking.

Perception is not reality.

Anecdote is not proof.

And trite little phrases add nothing to reasoned discussion.

Cycling is not more dangerous than walking

And neither does a bald and unreasoned assertion. Some of us prefer to
observe, reason, and then trust our resulting judgement.
Others end up on trolleys in A&E wondering why their trite little
mantras didn't protect them.

Toom

Colin McKenzie wrote:
PK wrote:
Cycling on the road needs constant vigilance to remain safe - walking
on the pavment needs the same level of viginalce only when crossing
the road. ....

And driveways, and entrances, and places where drivers may park on the
pavement, and places where drivers may take to the pavement to get round
a queue - in fact pretty much anywhere.

How many pedestrians a year get killed on the pavement? About 10% of all
ped deaths, ISTR.

According to the 2006 data from DfT, of the 675 pedestrian fatalities,
43 occurred on the footway *or* verge. There is no way of knowing how
many were actually on the "pavement", but certainly less than 6.5%.

--
John

On 9 Sep, 12:49, Peter Clinch wrote:
Toom Tabard wrote:
I walk in town, a lot more than and a lot further than the average
person. I no longer cycle in town, because I find it is unsafe, and it
certainly many times more hazardous than walking.

So if it's "certainly" more hazardous than walking, why doesn't that
show up in the DfT's stats?


Specifically, which statistics?

*When walking, you
only mix with traffic when crossing, and can freely choose, monitor
and control how you do that.

Up to a point: when you get to the place you have to cross then you have
to cross. *The fact that you can wait is a bit moot if the gaps aren't
there, and you have much less influence on the traffic than if you are a
part of it, as you are on a bike.


And you choose the place to cross. In the city where I live and where
walking is my main way of getting around I come across very few
situations, if any, where I cannot choose a place to safely cross.

*When you are cycling and permanently
interacting with traffic you have no such control.

You do, OTOH, have a lot more control over the traffic.

*When cycling safely
and considerately I constantly had near-misses which could easily have
had serious consequences. That rarely if ever happens when walking.

So how safely were you actually cycling?

In my own humble, and admittedly objective assessment, defensively,
competently and with a hazard awareness that comes form 40 years
interest in road safety issues, following six years professional
exposure to road accident investigation from the legal/insurance
viewpoint. I would hazard, if you'll pardon the expression, that most
of the events did not have serious consequences precisely because I
was cycling safely. If I'd been tanking along like many of my fellow
cyclists the results would have been different.

You "constantly" had near misses, yet they all missed, so how near were
they really? *I rarely have "near misses": might be my cycling, might be
the local driving, might be my perception...


Near enough to cause me sufficient perception of danger to stop me
cycling in town since walking is by comparison much more relaxing in
terms of safety. That is not to say I won't daydream and step out in
front of the number 42 bus today, but we're talking probabilities
assessed from experience.

ISTM you are possibly confusing actual safety with perceptions of
safety, and possibly perceptions of how safely you were cycling. *I see
quite a few people adding to their chances of danger when cycling
"sensibly", for example hugging the kerb.


Doing my best to eliminate the issues where my own misjudgements might
have contributed, there were still sufficient events where no
reasonable anticipation by me would have prevented the cycling hazard.

Toom

Toom Tabard wrote:
On 9 Sep, 12:49, Peter Clinch wrote:

So if it's "certainly" more hazardous than walking, why doesn't that
show up in the DfT's stats?

Specifically, which statistics?

The ones that give you serious injuries per unit time and unit distance.

And you choose the place to cross.

But you don't chose the traffic there.

In the city where I live and where
walking is my main way of getting around I come across very few
situations, if any, where I cannot choose a place to safely cross.

In the city where I live and where cycling is my main way of getting
around I come across few situations, if any, where I cannot choose a
place to safely ride.

In my own humble, and admittedly objective assessment, defensively,
competently and with a hazard awareness that comes form 40 years
interest in road safety issues, following six years professional
exposure to road accident investigation from the legal/insurance
viewpoint. I would hazard, if you'll pardon the expression, that most
of the events did not have serious consequences precisely because I
was cycling safely. If I'd been tanking along like many of my fellow
cyclists the results would have been different.

I'm glad you're sure that's "admittedly objective"!

Near enough to cause me sufficient perception of danger to stop me
cycling in town since walking is by comparison much more relaxing in
terms of safety.

Relaxation isn't about safety, it's about anxiety. If you don't like
cycling because it makes you anxious, fine, but that's not the same
thing as how safe you actually were.

Doing my best to eliminate the issues where my own misjudgements might
have contributed, there were still sufficient events where no
reasonable anticipation by me would have prevented the cycling hazard.

And yet you don't seem to have been killed in all that time...

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

On 9 Sep, 15:17, "PK" wrote:
"_" wrote in message

...


Neither does the average risk represent the individual risk.

if I'm not drunk, not a child, not very elderly and cross only at sensible
crossing points my risk as a pedestrian is far lower than the population
average. As *I pedestrian I control when I put myself in the zone presenting
the greatest risk of conflict with a vehicle *- the road. As a cyclist I am
there all the time.

For me, walking is much safer than cycling.



Indeed, and that is my experience. For the fit and aware adult walking
is by far the safer option, and, as you point out, in terms of the
objective safety comparison you have to compare similar populations,
not the statistics covering all pedestrians.

Toom