Some believe that smaller, more fuel-efficient vehicles are a key component of any sensible climate policy. But smaller cars, all else equal, tend to be less safe cars. Indeed, a recent report on much ballyhooed "minicars" finds that they are less crashworthy than normal sized vehicles.
The Insurance Institute for Highway Safety (IIHS) reported that in a series of test crashes between minicars and midsize models, minis such as the Smart car provided significantly less protection for their passengers.
The tests did not involve the much ballyhooed mismatches between subcompacts and Hummers, but measured the effect of relatively modest differences in size and weight. Even though the Smart car and other minis such as the Honda Fit and the Toyota Yaris have fared relatively well in single-car crash tests, they performed poorly in these two-car frontal offset collisions. In the words of IIHS president Adrian Lund, "though much safer than they were a few years ago, minicars as a group do a comparatively poor job of protecting people in crashes, simply because they're smaller and lighter."
That difference is reflected in the real world. The death rate in minis in multi-vehicle crashes is almost twice as high as that of large cars. And in single-vehicle crashes, where there's no oversized second vehicle to blame, the difference is even greater: Passengers in minis suffered three times as many deaths as in large cars.
Just as alternative energy sources are not free of environmental impacts, more fuel efficient vehicles have their downsides as well.
Causality has gone by the way board, as have such quaint ideas like 'the does makes the poison,' so I suspect anything goes, if it's politically expedient...
You've never heard of anyone being killed on the bump-o-car ride, have you? And those have been all-electric vehicles since at least the 1950's!
See http://www.iihs.org/news/rss/pr041409.html
And no, you don't necessarily get a race to the bottom because of the trade-off between safety, fuel-efficiency and other factors.
why? because they cannot maneuver out of accidents, thus they are more likely to get in one. at the point of impact, of course you want to be in an suv, however, the goal of driving is never to be in the impact in the first place which is more likely in a smaller vehicle.
Like so
So we'd be one carelessly drafted statute and an extra helping of dessert away from making Michael Moore himself illegal.
geokstr wins the thread best post this week.
That's actually an interesting exercise in statutory interpretation.
Suppose Congress enacted a statute saying only "Cars weighing more than Michael Moore are hereby prohibited." Suppose on the day the statute is enacted that Michael Moore weighs 300 pounds.
Suppose that one year later, Michael Moore weighs 350 pounds. Is a car weighing 325 pounds prohibited? The law was passed on a voice voice and not one in Congress entered any comments on the record before voting.
You already can if you get a hybrid. The Prius and Civic meet your parameters; the Camry and Altima are a little over weight, I believe.
Consumer Reports:
And on the IIHS tests:
As for the Nader-baiting, quoting a 1972 book is laughable. Engineering has evolved a bit since then, not least thanks to prodding by safety advocates. As for the EPA, um ... what's it's job again?
Kazman's obviously grinding a particular ax, but is he always so dishonest about it?
"People can have any car they want. They just have to push it."
So bigger cars cause risks to smaller cars, and we label the small cars "dangerous"? The conclusion is backwards. If we're going to use government policy to discourage the use of one type of cars, shouldn't we use the policy to discourage use of the cars and SUV's that cause the risk?
This statement indicates that small car manufacturers need to improve safety features of the vehicles, which is the type of information that the IIHS tests are designed to develop. This is good information. So calm down - the test wasn't designed to take away your Hummer.
Or maybe even:
Irresponsible people behaving stupidly don't kill people, Big Vehicles kill people.
Right?
You can't get a lot more exposed than on a bike, so presumably minicar drivers would be a bit better off than cyclists: the questions of manuverability and induced caution (very big on the bike scene) would therefore seem to be important in determining the actual minicar death rate.
Or how about:
The Yaris doesn't kill people, the Camry kills people.
But it's still interesting to characterize this as the smaller cars being less safe rather than the larger cars imposing more danger on others.
Also, how are we to make sense of the finding that "the Smart car and other minis such as the Honda Fit and the Toyota Yaris have fared relatively well in single-car crash tests" but also "suffered three times as many deaths as in large cars" in single-car crash tests? Does this mean that they performed better than midsize vehicles in single-car crashes but worse than SUV's? If they do better than midsize vehicles that's actually a surprising finding, and indicates that the small cars are safer than you would expect.
But this is not what these cars are designed for. The speeds and traffic patterns in cities--particularly, large cities--are much more friendly to these vehicles. Maneuverability and ease of storage/parking are essential qualities in city driving, but are far less important on a highway. Cost of maintenance and repair are also something to consider--even if the micro were totaled in a collision with a Land Rover, chances are, it would cost more to fix the Land Rover.
Bottom line is that we are not comparing apples to apples. Sure, there are some smaller cars that perform better in collision tests than larger cars (and not just "within the class"). And it is possible that the micros may eventually incorporate design elements that will make them safer. But, for now, we should be comparing their safety to that of scooters, not cars. It may also come down to banning them from interstates, or, at least, their non-urban sections--you know, the ones with posted speed limits above 55 mph.
Nick
The IIHS side impact test shows quite clearly that small cars can compete in tests comparable across weight classes. No doubt panicked by the result, the IIHS came up with a one-off, violent test that it will not subject any other cars to.
<i>And in single-vehicle crashes, where there's no oversized second vehicle to blame, the difference is even greater: Passengers in minis suffered three times as many deaths as in large cars. </i>
Not true. "Very large cars" have 11 deaths per million vehicles registered according to the IIHS. Minicars have 35 deaths. So the comparison is "Very large" to mini. Midsize have 29 deaths and large have 27. My guess is that vehicle miles have more to do with these numbers than anything else. "Very large cars," a category that only includes expensive luxury vehicles (and excludes trucks and SUVS) are not major sellers, not driven by the same sort of demographics as others, and are not likely driven as much. But if you think it is a reliable statistic, you must be willing to admit that both large cars and mid-size cars are extremely dangerous due to their more than twice as many deaths per million vehicles registered as the very large cars.
"The Effects of Mandatory Seat Belt Laws on Driving Behavior and Traffic Fatalities" Alma Cohen and Liran Einav
http://www.stanford.edu/~leinav/pubs/RESTAT2003.pdf
From the abstract:
This paper investigates the effects of mandatory seat belt laws on driver behavior and traffic fatalities. Using a unique panel data set on seat belt usage in all U.S. jurisdictions, we analyze how such laws, by infuencing seat belt use, affect the incidence of traffic fatalities. Allowing for the endogeneity of seat belt usage, we find that such usage decreases overall traffic fatalities. The magnitude of this effect, however, is significantly smaller than the estimate used by the National Highway Traffic
Safety Administration. In addition, we do not find significant support for the compensating-behavior theory, which suggests that seat belt use also has an indirect adverse effect on fatalities by encouraging careless driving.
.......................................
No, it's not a characterization, it's simple data analysis. You're more at risk in a smaller vehicle than a larger vehicle, in any type of accident.
And since, last I checked, 1/2 of all vehicle fatalities occur in single vehicle accidents, that means that 1/2 the current corpses will be produced no matter whether every other vehicle on the road with it is a Hummer or a scooter.
Mass is life. That should be intuitively obvious.
Yes, we will continue to advance in safety, and every single alloy in your vehicle is new since CY 2000, believe it or not. And they will change again as we advance, and hydroforming and additional body engineering methods will bring us further on, with increased strength and decreased weight.
But you can't legislate physics. All things equal, mass is life, and will be after those new methods come on line.... you will be safer in the larger vehicle then, too.
My daughter won't put her babies in anything but an SUV. You don't have to be an engineer to have common sense (but it helps if you're not a lawyer!)
Mass is life. That should be intuitively obvious.
***
My daughter won't put her babies in anything but an SUV.
Nonsense. Design differentiates safe vehicles from unsafe ones. Given that SUVs are often poorly designed, it is no surprise that they are among the least safe vehicles on the road. You are much better off with a comparably priced car or minivan than an SUV.
The thing SUV's generally provide that beats out average sedans is crush zone. Our soft bodies appreciate every inch you can place outside them, lest they be pierced. This is where the minis are death traps... not enough crush zone.
And the crush zone is proportional to mass. Mass is life.
I do agree that design is critical. So do my colleagues. But design can't overcome physics, as mentioned.
In a while, we'll have carbon fiber, very costly, unrecycleable, but that's about the only bridge I really foresee to the brave new world the congresscritters have planned for us.
This is where the minis are death traps... not enough crush zone.
Got anything to back that up? All synthetic tests show just the opposite. Real world numbers also show passengers, particularly child passengers, are safer in minivans than SUVs. Stability control cannot fully compensate for the unstable and poor design of SUVs. Properly designed, a vehicle does not need electronic intervention just to keep it upright.
And there is no "law of physics" that says anything here. Mass increases the severity of the accident. It most certainly does not, on its own, assist in survival.
No, the data show that design is most critical. Minicars rate much higher than the heavier compact cars both in synthetic tests and in real world numbers. If mass were so critical, this would not be true. Trucks and SUVs continually underperform similarly priced lighter cars even though they weigh much more. Why? In the first case, minicars are generally more expensive and appeal to a more upmarket consumer. Although still cheap, minicars are better designed than their smaller, cheaper counterparts. It is therefore not surprising that they are safer despite having a lower weight. In the second instance cars are safer than SUVs of a comparable price, because SUVs are poorly designed.
Yes, heavier cars tend to be safer, but this is more an artifact of design. Heavier cars are more expensive and are generally better designed. Price more than weight is the big issue here.
We can see this when we compare the US to other countries in deaths per vehicle mile travelled. Although the US is not bad in terms of safety, a large number of countries have fewer deaths per VMT. All of these countries have a smaller vehicle fleet. If mass truly were life, the US would be tops. Sorry to say it is not.
Spoken like a man who has never ridden in a deuce and a half. (That's an Army 2 1/2 ton truck...)
You are actually overstating their case. The study does not state that small light cars are necessary less safe than, say, a minivan, when crashing into something like a cliff that isn't going to move. Stating "all else being equal" strictly limited to multi-vehicle accidents between cars of different weights. In fact I can think of a number of fixed-obstacle crash scenarios where some types of heavier cars would be substantially less safe than the average mini car.
Really, it is Newtonian Physics 101.... When a small light object collides with a large heavy one, the momentum changes are shared equally, but not the velocity changes.
This being said, I still think that small light vehicles are a sensible part of any climate strategy.
That's the key here.
Simplifying it to an absurd degree there's basically three categories any given vehicle can have. Performance, Safety and Cost. Increasing any one characteristic will generally negatively affect the others. I'm including efficiency as part of cost here.
In the sense that they prize efficiency and small size (as well as cheapness) minicars are naturally going to performance and safety.
They could certainly increase safety while retaining the gas efficiency and small size, but that would make the cars much more expensive.
And never once do we consider that the DRIVERS are the problem, not the car sizes. More stringent testing and make licenses more expensive. Heavier penalties for failing to follow the rules.
If there weren't so many bad drivers on the roads, we wouldn't be having this same poo flinging contest over and over again.
.
A part of the calculus that isn't being discussed is performance. A heavier vehicle can be made to be as fuel efficient as a lighter one, but its acceleration performance will suck.
.
-- Wouldn't we be better off letting people buy fuel with MBTE mixed in? Gas mileage would go up 20% --
.
As in miles per gallon or miles per pound, mileage goes DOWN with an oxygenate additive, either MTBE or ethanol. Fewer BTU's in MTBE (fewer still in ethanol) than in an equal volume or mass of gasoline. If the MPG comparison is between methanol and MTBE, MTBE wins. But MTBE is essentially banned after being essentially mandated. Groundwater pollution. MTBE tastes awful in low concentrations, and tends to create a public scare of cancer and whatnot that is founded on pure ignorance.
.
-- You don't have to be an engineer to have common sense (but it helps if you're not a lawyer!) --
.
Imagine the conflicted souls that are both.
.
Helmets are mandatory in most states for motorcycle riders, on the correct fact that helmets reduce the rate of fatal injury. The same fact is unquestionably true for automobiles.
.
Just saying, the government could mandate circus-tiny automobiles (for the children's environment), and resolve the fatality issue by mandating helmets. Creative solutions will require looking at more than one variable (the mass/mileage/performance tradeoff in a car). Roadway design, radically reduced speed limits (e.g., 30 MPH if there are any trees, buildings, or other non-breakaway obstacles within some distance of the roadway), etc. are ALL available for legislated solutions.
Well, here's the problem.
There are always going to be lots of giant vehicles on the road - 18 wheelers, dump trucks, delivery vans, etc. Society just can't function without them. You can scream all you want about Hummers, Suburbans, Expeditions, etc. but most of the really big boys ain't going anywhere.
And as long as they are on the road, structural safety becomes a big issue, and then it's just a matter of basic physics.
fullerene, I was speaking of minis, as in cars, not minivans, which are safer than minis I agree. Anything is safer than a mini, and I see Reynolds posted a 3-wheeler dream mini on his site the other day. He must be a product liability lawyer.
Your data posted above confirms that minis are deadly, as mentioned. 35 deaths in minis as opposed to only 27 in large cars means a 30% increase in fatality. Adler's data is even more morbid at 200-300% increase, but we'll go with yours, since presumably you believe in it.
These numbers (representing a composite sample presumably, and you've given them on a per mile basis so I assume they are), confirm the "laws of physics" that should be intuitive to most. Mass is life. That 30% might be alive if they were in a larger vehicle.
18 wheelers, dump trucks, delivery vans, etc.
Most Kenworth drivers don't mistake their ride for an M3, unlike the Escalade and Expedition drivers. I'd be interested to know what the costs of combining freight, commuter, and tourist travel on the same roads is in terms of maintenance and lives lost, though. The poor surface quality of freeways (e.g., the 91 and 110 in Southern California) has got to cost lives and is mostly due to the presence of too much, too large traffic. The tourists doing 65 in the middle lanes while commuters and freighters weave and press around them has got to cost some lives as well. I wonder if there's any data comparing fatalities on commuter-dominated routes like the 73 toll road in OC vs. shared-use routes like the 5?
Your composite figure includes all cars, well designed, poorly designed, expensive, cheap... all of them. The discriminating factor in the data you've presented is mass, and that factor indicates that mass is life.
Other countries' data is interesting, but again, it's your data that we're dealing with... originating here... with the cars in the US fleet... on the roads here... real world customer usage data... right on the spot. No need to extrapolate, interpolate, or nothingate from other countries. It don't get no better than that, if you're doing hard analysis. We have the data in hand, which you've provided, and it indicates that mass is life.
.
Your moniker suits you. That time/mass/force analysis is a joke, right?
This would be an exceptional case. Again, the minis will not offer the crush zone a larger car offers, and it is this crush zone that spares life.
And the increase in crush zone is proportional to the increase in mass. You need the mass to gain additional crush zone. Mass is life, as the data above tells us. That extra few inches of crush zone around your body may be what keeps you out of the boneyard.
.
I'm going to speculate that the exceptional case einhverfr has in mind is in the nature of a cabover (virtually no forward crush zone) in a head-on collision with an obstacle at the same elevation as the driver. So, the vehicle might be a Class 8 (MASSIVE) truck, yet have high probability of death in certain types of collision.
sic 'em on that MTBE, boy!
What an incredible waste of money. Every wetted part in every fuels storage, transport, pipeline, pump, EVERYTHING had to be redesigned and often replaced to accommodate ethanol, which rotted out seals, etc. All because of a couple plumes somewhere, that the wrong gaggle of lawyers took and ran with. I think the ethanol bandits pushed it politically, too.
I get what rosetta is saying, now, though: since we're getting on an actual US roads with existing other drivers, one's best bet is increase your mass relative to others'.
.
Heh. Brings back memories. I have firsthand knowledge of how bad MTBE tastes in low concentrations, etc. I'm agnostic as far as MTBE being a good idea on balance, but it isn't the environmental catastrophe or health risk it is painted as.
.
-- I don't know if that qualifies as "analysis" and I probably got it wrong. --
.
Rosetta picked up the ball - mass is also necessary to obtain deceleration time (and to absorb energy), which puts your "mass is death, time is life" paradigm into the form of direct internal tension.
.
That too. but even in an impact with a stationary object, more crush zone improves your odds.
.
Take your paradigm to the extreme, and have zero mass available to crumple. You know, the "mass is death" thing. Just you and the obstacle (if you could magically obtain transportation as though being in a massless vehicle), and your deceleration will be higher than if you had some mass to crumple before you and the obstacle made contact.
F=Ma, yes, but that's only giving us the force at impact. Yes, the instaneous force during the event (quickly) changes due to deceleration, but the only time we're interested in the magnitude (or time of occurrence) of that instantaneous force is the instant it deforms enough body structure to pierce my unsculpted and often couchbound body. So "time" isn't really at issue I'd think, it's having enough body structure out away from me to keep my unsculpted body intact.
THe problem with this is that design is everything.
Those old sedans from the 60's had tons of mass and tons of "Room" but were still highly unsafe because because they weren't designed to crumple in a safe way. A head on collision simply drove the engine back into the passenger compartment.
What about NASCAR stock cars or Formula one cars? They have every humanly possible bit of mass shaved off, but for the kind of accident's they're involved in the level of safety is unparalleled. Of course 5 point harnesses and crash helmets help, but you try flipping a Camry into a wall at 160 even wearing a harness and crash helmet and see how well you come out.
Safety-wise car design is all about finding ways to disperse the energy from an impact without crushing the passengers.
It's true that having more space makes designing for dispersing that energy easier, but I will take a well designed small car over a poorly designed SUV any day of the week, and this is from a person who drives an SUV.
.
Yeah. The seat and driver cocoon designs are awesome. Same for hydroplane racing. Limit freedom of motion of the head relative to the neck and body, and there is a HUGE reduction in risk in collision. Literal crushing of the occupant is prevented with a roll cage.
.
There isn't a "perfect" answer, and we will always have fatalities. The number of them is higher when the government sticks its fingers in the design process (e.g., overpowered airbags; forbidding an airbag/seatbelt interlock arrangement)
Most fatal injuries in car accidents aren't like that.
They're either head trauma, or internal injuries that accompany rapid deceleration.
Many earlier SUV's were notably worse in the first category because of their tendency to roll over.
They're better in the second because mass plays a part in deceleration. You smack a golf ball with a bowling ball the deceleration of the bowling ball isn't going to be much.
Because of the way deceleration works, though even working 6 inches or a foot of place where the metal can crumple as part of deceleration will enormously reduce the G forces inflicted on someone. An SUV might be bigger, but it doesn't necessarily mean it has more space for metal to crumple in a way that reduces deceleration.
.
The formula necessarily has a time element, and applies at every instant. The difficulty in crash analysis comes from the need to segregate the various forces (crumpled zones are subjected to HUGE forces, uncrumpled/pristine zones, not so much); but really, the point is to keep the occupant's deceleration within certain parameters.
.
And on that one, a heavy person undergoing X deceleration will always impose greater force on the seatbelt/airbag than a lightweight person will.
Agreed, the magnitude of the force must be reduced, and it is the body structure that does that.
Head trauma is always problematic as you mention, and no matter how much head impact criteria you bake into a vehicle's design, your head is gonna bounce off that side window, and only a helmet will resolve that, or a side air bag (and if you're unlucky enough to roll or suffer a secondary impact, that won't help you).
Any late model SUV crash data I've seen indicates that those vehicles provide far more crush zone than certainly the minis or small cars. So they're bigger and safer, in my experience. Historically, it's been rollover that was their achilles heel, but that too is being resolved.
Thus, a regulation that forbade large cars on the road would probably actually result in lower risk for the average driver, because while it would increase the odds that you were in a small car (increasing your risk) it would also increase the odds that the other car was small (reducing your risk), and the second effect is more significant than the first (collision with an equal-mass vehicle is generally equivalent to a collision with a static barrier, and small cars do better in collisions with static barriers).
The point of crumple zones is to increase the deceleration time of the human body. A human body can only take so many g's and if you run into a wall at somewhere around forty miles an hour and your body decelerates from forty miles to zero, you are going to die merely from your internal organs striking your ribcage and skull. Crumple zones give your body more time to slow down. This is where a mini-car is bad news, instead of having the space of five feet of hood that crumples, dropping the engine onto the pavement, your body goes from forty miles an hour to zero in the distance of a foot or two--not good.
But of course crash worthiness is just one factor in car safety. More maneuverable cars with good visibility and low centers of gravity and good brakes are less likely to get in accidents. The true test is to compare real world accident rates based on accidents or injuries per vehicle or passenger mile. Even these can be deceptive because some types of cars (e.g., sports cars) tend to attract a more reckless demographic while others, perhaps because of their reputation for safety (e.g., Volvo) attract conservative drivers that might even enhance their safety record.
The 2012 Pelosi GTxi SS/RT Sport Edition
Get your order in now; they're sure to be flying off the showroom floor - or else.
It showed a 2-seater sports car after it had been crushed between an 18-wheeler and a concrete barrier. The car was a wad of tinfoil. The driver survived. Mass isn't everything -- design helps.
.
Indeed. And some accident scenarios mitigate the effectiveness of mass (e.g., head out the window, crushed in rollover). For the truck/car/barrier sandwich, resistance to crush could be everything, as the automobile occupant might be close to the barrier, and by dint of never obtaining much velocity, undergo very little acceleration/deceleration in the accident.
For the purposes of analyzing vehicle fatality by weight class, which I believe is the point of Adler's discussion here, we are analyzing entire classes of vehicles, not discrete vehicles (and their discrete "designs"). And in such analysis, the data shows a very clear trend.... that mass is life.
Now, I don't know which discrete vehicles/designs that that extra 30% (fulmerene) or 200-300% (Adler) of fatalities will occur in. I just know that this increase will occur across that class of vehicle. Those additional people will be dead.
At one point, NASCAR vehicles were constructed so rigidly that crash impacts were being transmitted to the occupant, because the roll cage was nearly indestructible. They are now engineered to better collapse upon impact and absorb the impact forces, while, as you noted, the driver's immediate environment is much more constrained.
cboldt -
Agreed. Something like 30% of driver fatalities and 50% of passenger fatalities involve the non-use of seatbelts. 30% of all fatalities involve drivers meeting or exceeding the definition of alcohol-impaired. This does bring to mind much of the publicity concerning the (lack of) roadworthiness of the late '90's Ford Explorer. The classic fatal accident scenario for the Explorer at the time was grossly under-inflated tires, being run at constant speeds far in excess of the speed limit and the tires' rated constant speed, resulting in overheating and tread separation, which wrapped around the axle and caused a vehicle roll-over, and last, occupant failure to wear seat belts and consequent fatal ejection. SUV's and light trucks are more prone to roll-over accidents, but usually they involve excessive speed for conditions and/or driver impairment.
In the real world, assuming one avoids driving drunk, one uses the restraint system, and one avoids confusing your SUV/pick-up with a Ferrari, I just don't understand how you wouldn't feel safer in a 5,000 pound vehicle than in a 2,500 pound vehicle, or in a vehicle with a passenger compartment which sits higher than the opposing bumper which is likely to bash into your door. If I'm willing to pay the gas penalty for less efficiency, so that my family enjoys a greater safety margin - assuming a sane driving profile - then I'm not sure why someone who takes a different point of view seems to feel they have veto rights over my decision. If you choose to drive a smaller, lighter auto, constructed of different materials, for reasons of economy - or even for reasons of saving our resources - then that's your right. But it does not somehow empower one to simultaneously deny me my same right of choice.
Geokstr -
Very funny. I had not seen that before.
Well, if you do analysis by the mass of the vehicle. If you do analysis by the mass of the other vehicle, the data shows that mass is death. The optimal safety situation for any given person is to be in the larger vehicle; the optimal safety situation for society as a whole is to have all vehicles the same mass. At constant mass, in theory a heavy sedan should be superior to a light sedan (and either should be superior to an SUV), but in practice the light sedan is enough cheaper that you can spend more on safety improvements, which cancels out any safety benefits you might get for weight.
Agreed that removing choice is undesirable - i'm just saying that you can quite voluntarily and sensibly choose a smaller, lighter, better performing car for reasons of safety.
BTUs per gallon is not the whole story. Both MTBE and ethanol raise the octane rating when added to gasoline. Some engines can take advantage of this increased octane rating and get improved mileage. If gasoline mixes with higher octane were the norm, manufacturers would design engines with higher compression ratios which would get more horsepower from smaller engines as well as better mileage.
There is also the fact that adding ethanol to gasoline causes it to burn cooler. In other words, some of those extra BTUs in nonoxygenated gasoline are used merely to make your car's radiator work harder to get rid of the extra heat generated with those extra BTUs.
Of course, I highly doubt that over half of the cars on the road are small...
Anthony, problem is, 1/2 of all vehicle fatalities occur in single vehicle accidents. For those victims, it doesn't matter what anybody else is driving... they're still dead. So best that they're driving the safest possible, and the data indicates more mass is safer.
Disagree with you that lighter, smaller vehicles are cheaper and easier to design. It is much tougher to package features, options, content, safety and performance in a smaller vehicle, as should be intuitively obvious. The "price per pound" curve, for product development, is not linear. As they say, "If you want a compact car, you have to pay for it."
That's generally additional product development cost, which yes may fall off when we finally churn through the tsunami of safety and fuel economy issues confronting the product development world these days, but they still exist. You can pick up a Crown Vic for less than a mini in some cases. I don't favor either one, but anyways...
So it's not as if there's some cost headroom available to cover additional safety in smaller cars.
I think you're circling around another part of this... that a sudden, arbitrary upheaval in the mix of the passenger vehicle fleet will have costs... in fatalities but also in dollars... and in the freedom to choose our vehicles as we wish. There is no free lunch.
"...you can quite voluntarily and sensibly choose a smaller, lighter, better performing car for reasons of safety."
In an ideal world, I would agree. But the driving environment in this country includes too many 18 and 80 year olds, and too many morons and drunks. You can be the most capable and professional driver in town, and still be toast when some drunk in a '79 Olds 98 runs a light and broadsides your small car. My SUV and pick-up both outweigh the average mid-sized auto because both have a full frame, and both have body panels of heavier gauge metal than, say, a Honda. They sit up higher (and have a higher CG, and thus might roll easier if pushed beyond design limitations) and generally offer more protection. They cost more, they use lots more gas, the license is more expensive, and people in hybrids sneer at me. I don't care. Lots more people in this country get killed by carelessness and cars than by deliberate murder. I carry a firearm to protect myself, but I'm much more likely to be the victim of aforesaid '79 Olds than another gun. There's a risk to driving a smaller auto, maybe an acceptable risk to most people, but a risk nonetheless.
At the time I recall being struck by the number of SUVs that I saw with one tire visibly underinflated, indicating (I'm guessing) a pressure of 10psi or less.
I'd recommend central tire inflation systems for all SUVs.
Full disclosure - I own a Smart car (which I drive on the highway - the turbulence from a truck is annoying, but hardly impossible to deal with). Whenever someone asks me about the safety aspect - my line is "as safe as anything else in its class." All other things being equal - size is safety in many collisions). The keys there are "all other things being equal" and "in many collisions".
They are also more likely to get in accidents because their drivers, thinking they are nigh invulnerable, drive like idiots. (See comments by trad and anon at 4.18.2009 5:56pm and by steingra at 4.18.2009 6:40pm about compensating behavior.)
If vehicles over a certain weight were banned, drivers would generally be aware they were driving unsafe tin cans, so paradoxically, there might be fewer fatalities because of drivers taking take extra care not to get in wrecks.
Moronic behavior, such driving and drinking, is not limited to operators of SUV's and pick-up trucks. If anything, judging from observed behavior within my own experience on limited access roadways, vehicles which are moving significantly faster than traffic flow and the posted limit, cutting in and out, and so forth, tend to be smaller sedans and sport coupes, not larger light-truck class stuff.
Agreed that you will be better off in those collisions than I will be in my Corvette Z06. However, I will be better off where the collision is in some way avoidable. I value the second ability more - you value the first. I won't interfere with your right to choose the first as long as you don't mind me choosing the second (and preferably don't imply that i'm some sort of dangerous lunatic for doing so). :-)
But now I'm old, and drive a truck, because I've seen too many fatals where the victim's only fault was wrong-place, wrong-time.
1) 2-car head-on collision. Here the heavier car is safer.
2) Rollover. Here mass is irrelevant in most cases and may be a hinderance in some. For example, a heavy SUV is more likely to break through a guard rail than a light sedan is.....
3) Offset crash, car into barrier. Mass of car is practically irrelevant (to get enough mass, you aren't going to be allowed to drive on the road).
4) Vehicle into wall/cliff. Mass is irrelevant.
Now, I was in a crash once (life saved by my seatbelt!) where my Ford Bronco broke THROUGH a guard rail and rolled. While I emerged with no injuries, many other things in the car were thrown out in the course of the accident. Were this a smaller car, the accident would have been very different and in fact might not have happened at all (combination of water on the road way and high winds, both of which disproportionately affected that sort of vehicle).
Now, if half of the fatalities occur in single-car accidents, you have NO way of generalizing from multi-car accidents as to the relative safety of different masses of vehicles.
If you have a comment about spelling, typos, or format errors, please e-mail the poster directly rather than posting a comment.
Comment Policy: We reserve the right to edit or delete comments, and in extreme cases to ban commenters, at our discretion. Comments must be relevant and civil (and, especially, free of name-calling). We think of comment threads like dinner parties at our homes. If you make the party unpleasant for us or for others, we'd rather you went elsewhere. We're happy to see a wide range of viewpoints, but we want all of them to be expressed as politely as possible.
We realize that such a comment policy can never be evenly enforced, because we can't possibly monitor every comment equally well. Hundreds of comments are posted every day here, and we don't read them all. Those we read, we read with different degrees of attention, and in different moods. We try to be fair, but we make no promises.
And remember, it's a big Internet. If you think we were mistaken in removing your post (or, in extreme cases, in removing you) -- or if you prefer a more free-for-all approach -- there are surely plenty of ways you can still get your views out.