[alancalverd]

.....it does not prevent damage to the head and neck. Military transports have the passenger seats facing backwards - much, much safer.   

Not that seat belts make much difference in civil aviation. Many people unbuckle them as soon as the wheels touch the ground, that is, when entering the phase of the journey most likely to incur sudden braking or collision. There's a lot of air upstairs, and very few aircraft, mostly 5 miles apart, but taxiways are narrow and occupied by all sorts of traffic.

It's a known fact that your IQ drops by 10 points whenever you sit in the pilot's seat, but the behavior of passengers, particularly on budget airlines,  is utterly baffling.  Your ticket says "one carry-on bag", but at least 20% of passengers are unable to count up to 1. Why do people stand in a queue for an hour before boarding, if they have assigned seats? Why do they pay for "priority boarding", which means waiting in another queue at the bottom of the stairs? Why do they stand up as soon as the plane stops moving, fight to encumber themselves with their precious one bag, then hang around in the aisle waiting for the doors to open? 

[Petrochemicals]

.it does not prevent damage to the head and neck. Military transports have the passenger seats facing backwards - much, much safer.   

The same could be said of most coach seats, they are only lap straps after row 1, i suppose the thinking is that you only need 3 point or more protection if you are somewhere near the front, plus complicated harnesses may hinder the evacuation process.

Funily enough the back of the head and neck injuries are not the things that seatbelts protect from, and probably create more of that sort. Seat belts prevent you from smashing your frontal cortex on the windscreen and dying, or maybe the rear passengers  flying through the windscreen face first, the fact that the neck and head are not supported mean that they continue and recieve whiplash. The way to prevent this is as they do in formula one, a helmet with an attachment point at the rear of it, it maybe something the AA should think about bringing in, after all a 500mph head on smash will no doubt lead to whiplash claims. But again this may hinder the evacuation efforts from a flaming winged petrol can.

[Petrochemicals]

What is white? If you shine an intense enough light on grey does it become white?

[alancalverd]

Whiplash is primarily caused by impact from behind - not a frequent problem with airplanes. Problem with sudden braking, runway excursion or head-on collision is passengers hitting the back of the seat in front of them.

[alancalverd]

What is white? If you shine an intense enough light on grey does it become white?

It becomes whiter.  "White" is very much a matter of perception, which is why detergent manufacturers include blue specks in their product to modify the spectrum emitted from nominally white materials.

[Bored chemist]

What Is Gray?
An American elephant.
Or, given the spelling.
https://en.wikipedia.org/wiki/Louis_Harold_Gray

[alancalverd]

After whom the unit of absorbed radiation dose is named. The LD50/30 is 5 gray.

[vhfpmr]

It isn't really practical to objectively quantify risk, because risk isn't objective.

Oh yes it is. Risk is the product of probability x impact.

The impact to you might depend on whether you have comprehensive insurance, that will affect your aversion, that will affect your behaviour, and that will affect probability. Risk isn't objective.

Give someone a seatbelt and they drive faster, which is largely why the projected benefits calculated from 'objective' risk never materialised.

Give cyclists crash helmets, and they end up with 30% more limb & torso injuries.

In most cases involving damage to humans we can ascribe an impact value of 1 to death and turn to the insurance market for a consensus of "partial death" injury values.

So you think that the insurance industry knows the value of your arm better than you do? Value to who, you or the economy? Which of those most affects your own behaviour?

people behave more carefully when they perceive more risk,

Apparently, after cyclones were given both male & female names (back in 1975), it was discovered that female-named cyclones killed more people than male-named cyclones. ("Cyclone" is Australian for hurricane.)
- I saw a speculation this week that female-named cyclones were perceived as less threatening than males, and so people took fewer precautions!

  Variously known as Risk Compensation, Risk Homeostasis, and in the insurance industry, Moral Hazard. I like that one, I'd not seen that before.

Cars kill ~1500 Brits a year, I don't think that many are killed by planes, what's in operation is the Availability Heuristic: people perceive probability according to how easily something springs to mind.

I know more people who have been in car crashes than have been in plane  crashes.
So the "availability" argument isn't convincing.

Plane crashes are more available because

newspapers etc publish stories about 10 people dying in a plane crash but not about the 25 killed on the road each month precisely because people are more interested in rare events involving a moderately large number than in the thing which kills a lot more people, but by a steady drip feed of corpses.

Wave the plane crashes in their faces every verse end, and that's what people will notice.

Seat belts prevent you from smashing your frontal cortex on the windscreen

But not on the steering wheel.

[alancalverd]

So you think that the insurance industry knows the value of your arm better than you do?

Any insurance policy is a negotiated contract.

You decide how much your arm is worth: the insurer estimates how likely you are to lose it (i.e. the risk: probabiity x impact), and offers you a premium to cover that amount. There are some standard policies that represent previous court settlements for injury to Joe Average, the cost of motor vehicle repairs, house fires, etc but an athlete or a musician might require a higher figure for certain personal injuries.

[Petrochemicals]

Give someone a seatbelt and they drive faster, which is largely why the projected benefits calculated from 'objective' risk never materialised

Nonsense, most people drive in a way to prevent damage to their car, seat belt or no, the idea of imminent demise is not really a thought.  Seatbelts save lives.

But not on the steering wheel

yes even on the steering wheel.

[Bored chemist]

Nonsense, most people drive in a way to prevent damage to their car, seat belt or no, the idea of imminent demise is not really a thought.  Seatbelts save lives.

OK imagine that one day you are asked to drive to a meeting across town. They give you  an armoured truck to make the trip.
Then, the next day, for the  same trip, they give you a rickety old schoolbus  which has a bottle of nitro-glycerine on the  next seat and dodgy suspension.

Do you drive the same way in both cases, or do you adjust your driving according to the apparent risk?

Anyway, here's some data. from
https://en.wikipedia.org/wiki/Reported_Road_Casualties_Great_Britain


Seat belt death.png (118.79 kB . 1024x650 - viewed 1513 times)

[evan_au]

It's sometimes called the Peltzman Effect, named after a Chicago economics professor.
- He wrote a paper arguing that road safety measures weren't worth the cost, because they didn't save any lives.
- Apparently, the numbers in Peltzman's paper were later found to be in error; 
- Subsequent work suggests that the gain from some safety measure is up to half offset by more risky behaviours (the comment about bicycle helmets suggests a 30% offset).

Maybe Peltzman was more worried about the effect on purchase price than the effect on human life?
https://en.wikipedia.org/wiki/Risk_compensation

[Bored chemist]

The immediate effect of teh introduction of Davy's safety lamp was an increase in mine explosions.
Previously, people didn't even try to work in "gassy" mines.
With the lamp, they could do so.
And when a pickaxe struck a spark...

[Petrochemicals]

- Subsequent work suggests that the gain from some safety measure is up to half offset by more risky behaviours (the comment about bicycle helmets suggests a 30% offset).

Any correlation in a graph between road deaths and seat belts is highly dilute. For example it can be refuted by the following graaphs

Screenshot_20240121_165734_com.android.chrome~2.jpg (131.19 kB . 1920x1131 - viewed 546 times)car ownership

Screenshot_20240121_165707_com.android.chrome~2.jpg (192.5 kB . 1920x1137 - viewed 569 times)bicycle ownership

As you can seeevwn though car ownership goes up, road deaths come down with the drop in bycycle ownership.

[vhfpmr]

So you think that the insurance industry knows the value of your arm better than you do?

You decide how much your arm is worth

So how much will you sell me your arm for then? Mine aren't for sale.

Give someone a seatbelt and they drive faster, which is largely why the projected benefits calculated from 'objective' risk never materialised

Nonsense, most people drive in a way to prevent damage to their car, seat belt or no,

Janssen at the Dutch transport research labs says otherwise, because unlike you, he's done the research.

the idea of imminent demise is not really a thought

Your conception of risk compensation is utterly naive, almost all of the behaviour is completely subconscious. All it takes to wipe out the benefit of seat belts is one extra death every few million miles travelled, no single individual even has that amount of personal experience, let alone the ability to perceive it.

Seatbelts save lives.

Professor John Adams at UCL is the guy who did all the research into seatbelts for the government prior to their being made compulsory. He found that nowhere in the world had been able to demonstrate a reduction in road deaths attributable to the introduction of compulsory seat belt legislation. His work was peer reviewed by the DoT, but HMG chose to ignore it, and legislate anyway. The initial legislation was for a temporary trial period, during which time the DoT report was leaked to New Scientist, but the HMG and society in general still ignored it, and so the law became permanent.

But not on the steering wheel

yes even on the steering wheel.

The piece of my nose bone that I dug out of the steering wheel in this says otherwise:


TR7 #2.jpg (44.79 kB . 466x322 - viewed 702 times)

As I said above, virtually all of risk compensation is stark staring obvious, and yet people will fight tooth & nail against it when it contradicts their own vested interests.

It's sometimes called the Peltzman Effect, named after a Chicago economics professor.
- He wrote a paper arguing that road safety measures weren't worth the cost, because they didn't save any lives.

It's more complicated than that, because the probability of changing your behaviour will depend on your perception of the effectiveness of the safety device. Paradoxically, that means those most likely to benefit from a helmet are the ones who think it's least effective.

The immediate effect of teh introduction of Davy's safety lamp was an increase in mine explosions.
Previously, people didn't even try to work in "gassy" mines.
With the lamp, they could do so.
And when a pickaxe struck a spark...

Yup, John Adams cites this example of risk compensation.

Another interesting one is that motorists who cycle are half as likely to crash their cars than ones who don't.
Why? Because they see the roads from both sides of a car windscreen and experience the treatment meted out to cyclists first hand, and so have an entirely different perception of the risk on the roads. Cyclists can even get a discount off their car insurance.

83% of cyclists drive, and know what they're talking about, 70% of motorists don't cycle, and from years of arguing with them on Twitter I can say they generally talk out of their bums.

Walk a mile in another's shoes, and all that.

car ownership goes up, road deaths come down

It's been known for decades that road deaths correlate with traffic density, not safety devices: busy roads look more dangerous, so people drive more carefully on them.

[Petrochemicals]

The piece of my nose bone that I dug out of the steering wheel in this says otherwise

You where alive to dig it out.

[Petrochemicals]

It's been known for decades that road deaths correlate with traffic density, not safety devices: busy roads look more dangerous, so people drive more carefully on them

Unless they have seatbelts, as such they start screaming around like a stock car racer with a death wish?

[alancalverd]

Another interesting one is that motorists who cycle are half as likely to crash their cars than ones who don't.
Why?

Because most road accidents occur within 5 miles of the home of one of the drivers. If you have a bike, you are less likely to use the car for short journeys! 

[alancalverd]

So how much will you sell me your arm for then? Mine aren't for sale.

Standard compensation claim for one arm (solicitors' guidance)

Above the elbow, GBP102,890 -122,860, below the Elbow GBP90,250 - 102,890

More for younger people. Self-employed would probably choose 2 - 5 times that level of insurance.

[evan_au]

What Is Gray?

I heard there are 50 shades of Gray...