David L. Johnson wrote:
> > Safety is defined in terms of the relative risk to the occupants of vehicles.
> That is a myopic definition.
It is the standard, customary definition.
At least you didn't make an ass of yourself about this, this time.
And you have to understand one thing: what are the relative severity of consequences of different
collisions? Aside from a non-yielding object that is struck, the worst event normally is colliding
with another vehicle. Collision safety or relative risk to one's self is not only the customary
definition but the primary measure of safety for just this reason.
> It should include the relative risk to those the damn thing hits, too.
That is, sadly, an excuse used by the whinier leftiests to get vehicles to be shrunk, no matter
what reality demands. But the concept has always been there, such as when reminding motorists not
to linger or be risky at railroad crossings, such as trying to beat the train...
Studies now often address the "threat" to others as well as the risk to one's self as an occupant.
(See below, bottom of posting.)
> > Pickups, SUVs, and cargo vans are heavier and in addition, they are more sturdy (you can
> > review safety studies which refer to their stiffer frames and such if you are interested), and
> > they overall are safer to their occupants, in all kinds of accidents.
> Again, this is a matter of definition.
There is no reasonable complaint about the definition. There is a related, secondary, concept,
which addresses exactly what you discuss, which is the relative risk of some vehicles to other
vehicles (and by implication, to other things like cyclists, pedestrians, or buildings, or
whatever).
> "Safer in all kinds of accidents" restricts attention to the results of accidents, not the
> likelihood of having one. Rollover statistics are swept under the rug in this calculation, and
> SUVs are notoriously prone to rollover. In a given situation, had the driver been driving a
> sensible vehicle, he/she would not be in the accident statistics at all, since it would not have
> rolled over.
They are not swept under the rug; they are smaller than the relative safety to occupants in large
and sturdy versus small and less-sturdy vehicles. The other issues are there (which include, as I
mentioned, different vehicle ride heights).
> > Where there is a greater, not smaller, relative risk with the vehicles ... is that their
> > higher centers of gravity present a higher risk of rollover.
> but then you go on to ignore this effect:
I don't ignore it. I posted it above, and it's part of the entire picture. It's simply not the
only part and it's not the major part, and activists who push this part are being less than
completely honest (or mature).
> > In typical safety studies, the smallest cars are, as expected, at the very bottom and far
> > riskier than the bigger vehicles. As far as the secondary element of risk to other vehicles
> > (the issue which the leftists currently are flogging to death, and being silly when not
> > irritating or outrageous) is worst with cargo vans, not pickups or SUVs.
(In fact, the term used irritates better people but it is becoming used anyway: the secondary
risks to others are referred to in studies with the smarmy left-wing-implied sound-bite phrase
"VEHICLE AGGRESSIVITY.")
(If you want to do research on your own, a good idea is to do a Web search for the term "vehicle
aggressivity" both as a phrase and with separate words.)
> Well, excuse me for voting Democratic,
That's OK. Nobody's perfect. You have plenty of company, though
the kind of company it is should make you feel not better, but worse.
> but that is irrelevant.
It is not. You are free to read studies on relative risks if you want to learn more. I will add
some information below (end of posting).
> Actually, the "worst" [in terms] of risk to other vehicles would be logging trucks.
I wouldn't want to tangle with a fully loaded moving van, myself. Anything that slows down to a
crawl on upgrades is something I'd take extra pains to avoid in a collision.
> But the number of logging trucks on the road, or cargo vans, is a small fraction of the number of
> Ford Explorers.
Cargo vans have not been part of the contemporary vehicle preference trend, yes.
Far too many people don't realize that the real problem with hazards has very little to do with
the kind of vehicle, and is independent of vehicle choice and especially trends disparaged by a
strident minority. The main source of vehicle problems remains the nut behind the wheel.
You may not like the trend toward larger truck-based vehicles and the raised risk to yourselves,
the non-motorists, but the motorists find them safer* and they are safer given the normal
definitions. Nobody is ignoring the secondary risks to others from the greater truck-based vehicle
weights and character of the vehicles (sturdier, higher-riding). However, we live in a free
country and even if you (as a Democrats, you are more likely to) dismiss this as a worthless
issue, you also must understand that many purchasers of trucks do so because they need the hauling
or towing capability, even if only on the weekends to haul a boat, for example, rather than use a
truck on the job (which many do, with all kinds of equipment or other items in the truck bed).
Nobody disputes that many people use truck-based vehicles as automobiles (such as for commuting),
but you cannot treat both apples and oranges as apples (force both to get the same kind of
emissions, fuel efficiency, or lowered weight). Any alternative lighter-weight vehicle faces the
same real-world test of seriousness that does alternative sources of motive power -- performance
must be similar, and so must be price, if not even better for the alternative to induce a switch.
A titanium or composite-fiber truck that can carry same-sized payloads but is lighter-weight to
get better fuel efficiency is not the answer if the cost of the vehicle is several times more than
ordinary steel or a steel and aluminum combination, for example. (And with changing from steel to
aluminum, one must address the high energy costs for obtaining the aluminum in the first place.)
* A cynical additional thesis I have encountered is that because the sturdier truck-based vehicles
can handle poorer roads, some argue that motorists switch from cars to trucks when roads are
poorly maintained rather than agree to spend more tax money on roadway improvements.
Some items follow. There's much in there for everybody, but the main issue remains that lowering
vehicle weights would tend to increase fatalities, and any "safety" argument ends up in against
weight reductions. Bigger IS better.
"Vehicle size and weight are important characteristics that influence crashworthiness. The laws of
physics dictate that, all else being equal, larger and heavier vehicles are safer than smaller and
lighter ones. In relation to their numbers on the road, small cars have more than twice as many
occupant deaths each year as large cars.
Size and weight are closely related. Large vehicles typically are heavy, and small ones are light.
But these two characteristics don't influence crashworthiness the same way. Vehicle size can protect
you in both single- and two-vehicle collisions because larger vehicles usually have longer crush
zones, which help prevent damage to the safety cage and lower the crash forces inside it.
Vehicle weight protects you principally in two-vehicle crashes. In a head-on crash, for example, the
heavier vehicle drives the lighter one backwards, which decreases forces inside the heavy vehicle
and increases forces in the lighter one. All heavy vehicles, even poorly designed ones, offer this
advantage in two-vehicle collisions but may not offer good protection in single-vehicle crashes."
http://www.iihs.org/vehicle_ratings/sfsc.htm
"The results have a clear pattern: reducing a vehicle's weight increases net risk in collisions with
substantially larger and stronger entities, reduces net risk in collisions with much smaller and
more vulnerable entities, and has little effect on net risk in collisions with vehicles of about the
same size. The only entities smaller than passenger cars are pedestrians, bicyclists and
motorcyclists. Therefore, when car weight is reduced, the modest benefit for pedestrians is far
outweighed by the increase in most other types of crashes. The latest light trucks, on the average,
weigh over 900 pounds more than passenger cars. Continued growth in the number and weight of light
trucks is likely to increase the hazard in collisions between the trucks and smaller road users
(cars, motorcyclists, bicyclists and pedestrians), while a reduction in the weight of the trucks is
likely to reduce harm in such collisions.
Some people believe that small cars attract aggressive drivers because they are more sporty and
powerful than large cars. They might argue that, to a greater or lesser extent, it's not the cars,
but rather their drivers that are responsible for the higher fatality rates of small cars in the
preceding analyses. This belief may have been valid at one time, but today, the typical small car is
no longer a sports car. The make-models currently associated with high performance, high horsepower,
or aggressive driving are generally not small, but are of average or even slightly
heavier-than-average weight. As a result, the high-performance make-models, if anything, biased the
preceding analyses in favor of smaller cars. In a sensitivity test, the analyses of this report were
re-run without those sporty and high-performance make-models. The correlation between passenger car
weight and fatality risk did not diminish. In fact, it became slightly stronger. The predicted
effect of a 100-pound weight reduction escalated from an increase of 302 fatalities in the baseline
analysis to an increase of 370 fatalities on the sensitivity test."
http://www.nhtsa.dot.gov/cars/rules/regrev/evaluate/808570.html
*** "Vehicle Aggressivity," Compatibility, Various Ideas for Reduction, Etc. ***
Worldwide
www-nrd.nhtsa.dot.gov/pdf/nrd-01/ esv/esv17/proceed/00135.pdf www-nrd.nhtsa.dot.gov/pdf/nrd-01/
SAE/SAE2002/SSummers_SAE2K2.pdf
USA
www-nrd.nhtsa.dot.gov/pdf/nrd-11/17ESV_249.PDF www-nrd.nhtsa.dot.gov/pdf/nrd-11/esv96cg.pdf
www-nrd.nhtsa.dot.gov/pdf/nrd-11/aggress1.pdf www-nrd.nhtsa.dot.gov/pdf/nrd-11/SAE2001-01-1172.pdf
www-nrd.nhtsa.dot.gov/pdf/nrd-11/15ESV_96S4O01.pdf www-nrd.nhtsa.dot.gov/pdf/nrd-11/
1999_SAE_Compatibility_Paper.pdf www-nrd.nhtsa.dot.gov/pdf/nrd-11/esv98cg.pdf
www-nrd.nhtsa.dot.gov/pdf/nrd-50/ ciren/2001/0901nhtsa.pdf
Rollover Stability and Rollover Crash Protection...
www-nrd.nhtsa.dot.gov/pdf/nrd-01/esv/ esv18/AbstractBookletDraft3.pdf
Dave Simpson
