This reaction from Michael O'Hare is about typical of the forceful response this drew from proponents of higher fuel standards:
The facts behind the story are that in a collision between a big car and a little one, the little one will be much more damaged and the people inside more hurt. Now you might think this could be thought of in more ways than one, for example that people who choose to drive big cars are putting others at risk, kind of like people who have large vicious dogs, or smoke in bed in apartment houses, or open their car doors without looking back to check for bikes.
. . . Excuse me: why is oversizing and up-weighting not the behavior associated with an increase in deaths on the highway? Why is the "standard" car the fat, thirsty, heavy vehicle of the reckless and self-indulgent? The excess injuries are associated with different sized cars, not small cars; why is the IIHS blithely fomenting an arms race for bigger cars, instead of demanding much higher premiums to insure the road yachts that put sensible people at risk for doing the right thing?
But this is not true, at least according to the IIHS. The IIHS is, of course, a corporate funded organization--but it's funded by insurance companies that don't like paying accident claims for severe injuries and deaths. And what the report says is that small cars fare much worse than mid-sized cars, not in collisions with hummers, but in collisions with Honda Accords and Toyota Camry's. They also do worse in single car accidents.
The death rate per million 1-3-year-old minis in single-vehicle crashes during 2007 was 35 compared with 11 per million for very large cars. Even in midsize cars, the death rate in single-vehicle crashes was 17 percent lower than in minicars. The lower death rate is because many objects that vehicles hit aren't solid, and vehicles that are big and heavy have a better chance of moving or deforming the objects they strike. This dissipates some of the energy of the impact.Some proponents of mini and small cars claim they're as safe as bigger, heavier cars. But the claims don't hold up. For example, there's a claim that the addition of safety features to the smallest cars in recent years reduces injury risk, and this is true as far as it goes. Airbags, advanced belts, electronic stability control, and other features are helping. They've been added to cars of all sizes, though, so the smallest cars still don't match the bigger cars in terms of occupant protection.
Would hazards be reduced if all passenger vehicles were as small as the smallest ones? This would help in vehicle-to-vehicle crashes, but occupants of smaller cars are at increased risk in all kinds of crashes, not just ones with heavier vehicles. Almost half of all crash deaths in minicars occur in single-vehicle crashes, and these deaths wouldn't be reduced if all cars became smaller and lighter. In fact, the result would be to afford less occupant protection fleetwide in single-vehicle crashes.
Yet another claim is that minicars are easier to maneuver, so their drivers can avoid crashes in the first place. Insurance claims experience says otherwise. The frequency of claims filed for crash damage is higher for mini 4-door cars than for midsize ones.
The outrage at the Times is not reality based. Small cars simply are not as safe as bigger cars, and they can't be made safer by yelling at people who insist on believing in the laws of physics.
I say this as the proud owner of a used Mini Cooper S. I was aware when I bought it that it was not as safe as owning an SUV. Like the hippie environmental whacko moralist I am, I believe that I have an obligation to drive the smallest car possible, when I drive, even at some extra risk to myself. I also like the gas mileage, the extreme ease of parking, the turn radius, and, yes, the styling. Life is full of tradeoffs.
On the other hand, I live in a city, and do most of my driving at speeds well below lethal. My bullmastiff does not require a carseat. And my recently formed household includes (rare for DC) a second car, a midsized sedan that can be used for highway driving. It's not as if I've really leaned into the strike zone to take one for the team.
As long as Americans insist on having children, and those children are legally required to spend their prepubescent years in some elaborate safety contraption, American cars aren't going to get much smaller than an Accord. And those Accords will continue to pose a mortal threat to those of us who drive smaller cars.
This is a real problem for proponents of higher fuel economy, not to mention the manufacturers of small cars. Cheap, fuel efficient cars are more dangerous. Even hybrids rely at least in part on making the car lighter. On the other hand, running a massive uncontrolled experiment on the global climate seems kind of dangerous too.
I have no problem accepting this as true as far as what happens in a crash.
On the other hand, doesn't light weight, handling, and maneuverability mean that you might not get into a crash to begin with? That is, avoid the accident. I've had a number of instances driving subcompacts (two really scary times especially) where I was able to swerve and brake to avoid a collision. That wouldn't enter into the equation, but surely it's important for safety.
The other thing that I've noticed driving a 1970 TR-6, is that if you feel vulnerable, you will drive more defensively. That means obsessively keeping an eye on other drivers to make sure they see you, no eating or drinking, and for sure no talking on the phone. I think driving a more "dangerous" car can make one into a safer driver, at least while behind the wheel of that same car.
Chris
For those that would rather keep out of a crash, visibility and control might count for more than generous crumple zones. Not that tiny cars have any inherent edge there -- the Mini probably does, but not the Smart -- but 5,000 lbs+ SUVs are bound to be the dancing cow of the bunch. Thus it's the mid-to-compact sedans and station wagons we should be elevating, not SUVs or subcompacts.
Yes and no, heavy cars certainly have more single direction momentum, which inhibits quick swerving. But they're much less prone to fishtailing or losing control in the snow.
I remember being in an overloaded Toyota Corolla (not even the smallest of the bunch) with 5 people + luggage and doing fishtails followed by a 360 across the Southern State Parkway before flying about 10 feet up an embankment. Fortunately nobody was hurt.
Ah, snow... that thing I have a bit of in the fridge :-)
I agree, the actual winter (as opposed to what we have in TX) makes a difference. However an AWD Audi or Subaru with winter tires is certainly going to run [well-controlled] circles around any heavyweight SUV even then.
A good driver is a good driver, more dependant on will and training than car size. I've driven cars of all sizes, and I'll put my adjustable 4WD V8 Explorer with AdvanceTrac and Anti-Lock up against any Audi or Suburu in any weather. Also, my brother has a fun-to-drive Mini Sport, but his family doesn't fit into it so they normally take 2 cars everywhere (the Mini and his wife's Camry), which isn't exactly better for the environment. Me- I fit my family and 3 dogs in, every time. Point being, "small" isn't better..."sensible" is.
One thing people often overlook is that even in car to car accidents, the vehicles still often impact stationary objects like guard rails, trees, and the ground itself.
Now is as good a time as any to post the following:
The crash test of a Renault Modus vs. a 1990's Volvo wagon.
http://www.youtube.com/watch?v=k3ygYUYia9I
You will see in the video the tiny Renault destroy the much larger Volvo.
Gotta love it when enviro-activists bump into reality. Also in the news, solar and wind power will never ever provide a significant share of electricity.
Chris:
Most cars can out-drive most drivers. The driver is the weak link in that chain, as a good driver in a large vehicle can out turn or out brake an average driver in a more nimble one. If you choose not to believe this, how else would you explain that smaller cars get into more accidents than their mid size cousins?
I don't disagree that the driver is the weak link. My point is that the driver of a small vehicle has an incentive to be a good, defensive driver, and I think that counts for something as far as accident-avoidance. One may be a better driver out of a sense of self-preservation, which wouldn't necessarily be the case (or not as high a priority) in a big vehicle.
(I say this as one of the 90% of drivers who think themselves as above-average!)
My observation of the driving pattern of those in Miatas contradicts this.
What you are hinting at, without actually saying, is driver demographics. For many practical reasons, which size and type of vehicle is the average young driver more likely to own and operate?
It's no mystery that smaller cars don't perform as well in crashes as larger ones, but that recent IIHS report was still very disturbing. It would've been predictable if the three tested minicars (Smart, Yaris and Fit) had performed poorly if crashed into large SUV's, but what actually happened is that they were crashed into not-very-large sedans (C-Class, Camry and Accord) and still performed dreadfully. The Smart was the best of the bunch, for although it caroomed like a billiard ball after fetching into the C-Class its passenger compartment was at least more or less intact. The Yaris ... good god, after smashing into the Camry it suffered massive intrusion into the passenger compartment, to the point that there really wasn't sufficient remaining survival space for the driver. That's horrible.
The Smart may not have had much impingment on the passenger compartment, but sudden acceleration like that will do a lot of damage.
I worked with a guy who got in an accident like that - he had on his seat belt, there was an airbag, and after everything stopped spinning his body was relatively unscathed. But somehow the G-forces twisted his brain stem inside his head. I don't know the technical term. It was like he suffered a moderate stroke - couldn't remember words, slurred speech, and clumsy.
And for those of you who think your l33t driving skills can prevent a crash - he was in stop-and-go freeway traffic and the guy behind him fell asleep. The time lag between my coworker realizing the guy behind him wasn't gonna stop to the impact couldn't have been more than a second or two. He had nowhere to go, anyway, since there was someone ten feet off his front bumper.
"The frequency of claims filed for crash damage is higher for mini 4-door cars than for midsize ones."
I have a lot of respect for the quantitative and analytical abilities of the insurance industry, so I'm guessing that something is getting lost in translation, but there are at least two problems with the assertion and the implication made here:
1) It is easier to do damage to a minicar than to a mid-size car, even in a single-car accident. Therefore, given equally frequent accidents, we would still expect more insurance claims for mini-cars.
2) The correct comparison would require controlling for all other risk factors. If the typical operator of a minicar is more likely to be involved in an accident than the typical operator of a midsized car, then it is impossible to conclude anything about the car's contribution to accident frequency.
Having made these objections, it's still fairly self-evident that at some level trade-offs have to be made between safety and efficiency.
This blog helps me lose weight.
Because when I read collectivist claptrap such as "Like the hippie environmental whacko moralist I am, I believe that I have an obligation to drive the smallest car possible, when I drive, even at some extra risk to myself" and "It's not as if I've really leaned into the strike zone to take one for the team" written by someone who used to blog under the name "Jane Galt", I throw up a little every time.
Megan, did you start eating paint chips when you went to work at The Atlantic?
It's not like she said she wanted to force everyone else to live according to her morality, it's just what she chose for herself. There is nothing inconsistent about being a moral libertarian.
To be fair, she's never been a Randite, she just used that name to piss off people on NY Times comment threads. Megan's always been a fairly moderate libertarian, at least for as long as I've been reading her, and a comment like that would seem to have fit just as well on Asymmetrical Information back in '03 as it does here and now.
Also, pollution is a negative externality, a legitimate harm to others. Even if you don't buy into global warming, the more conventional pollutants out a car's tailpipe are things best minimized. Minimizing active harm to others when possible is hardly antithetical to even the hardest-line libertarian positions.
In the last decade, I've lost two friends to accidents; one driving the "safest" car, a volvo -- her car was crushed by a pulp truck (a truck used to carry logs), the other was in an SUV that was hit by a tractor-trailor hauling a heavy cargo. In both cases, it was the truck-drivers fault.
Perhaps the insurance industry should be aiming to get more trucks off the roads, their cargos onto trains, and for expanded rail transportation.
A pulp truck? Jeez, sometimes your number is up.
Meghan--this is a good micro-example of the macro problem of today's Americans being unwilling/unable to accept the existence of trade-offs in life. Lefties, righties, moderates, whatever. You cannot drive a compact car and save all that gas and environmental damage and expect to be perfectly safe at all times, no matter what happens. As you noted, the laws of physics say otherwise. So why are we so surprised about the crash test results? Why is this such a revelation? Why the outrage?
If the cycle holds in this particular instance, we will have congressional hearings into small car safety. There will be lawsuits from people hurt in small car accidents, even if it was their fault, claiming that NO ONE EVER TOLD THEM that, you know, when you drive your Mini Cooper head on into something larger and denser than said Mini, you will not have the same crash protection as you would in a Ford Explorer. The environmentalists will propose a ban on larger vehicles. Then the safety advocates will propose mandating better safety regulations for small cars, thus reducing the environmental benefit.
In the end, we'll get a watered-down incremental change. Will the environment benefit? Not much. Will small car safety improve? Not much. Will the lawyers and lobbyists get rich? You betcha.
Did you miss the paragraph where she says she's aware her Mini is not as safe as a larger car? Where she says she's knowingly and willingly made the trade-off between safety and her environmental beliefs?
Did you miss the part where I said "...Americans being unable/unwilling to accept...", as in Americans in general, and not Meghan in particular? Or how about the part where I said "There will be lawsuits from people hurt in small car accidents...", as in the larger population, not Meghan herself?
And there's the added increase in premiums likely to occur for compact cars now that there's research to back it up and a likely surge in sales coming.
But hey, insurance has got to make up for the financial losses in the stock-market bust lately, too. Remember: they invest those premiums.
In my Miata, I've noticed a lot of SUVs and trucks try to change lanes into my lap when they're to my left, especially when I've got the top down. This is because the highest point of my car is below their passenger-side windowsill. I noticed that before I bought the car. They don't know I'm there. If they hit me, that little car will crumple up like a beer can and I'll be dead.
My solution is to pay attention and dodge them. It's hardly grandiose enough to suit O'Hare, but it has the (debatable) advantage of saving my life right now. O'Hare's method is simpler: Instead of assuming the nightmarish burden of paying attention when he's behind the wheel, all he wants to do is replace millions of vehicles and make millions of people think about driving in a different way. Or maybe he just wants to tell them they're stupid. That'll help.
You're wrong, though, Meg, in bringing up collisions with non-vehicle objects. That's not relevant, because in O'Hare World, all the bridge abutments and telephone poles will be too small to hurt anybody. They will also be brightly colored. All that's required is that we learn to relate to bridges in a more thoughtful and reflective way.
Chris A.: Your argument in favor of "more dangerous" cars, as a way to promote safer driving, used to come up in defending the old 16-bit Mac OS's lack of protected memory: "It forces programmers to root out all their pointer errors!", some said. But it didn't, because the limiting factor wasn't the will of the programmers to find and fix all of their bugs; it was the fact that finding and fixing all of your bugs is physically impossible. Oops.
Your experience with your Miata reminds me of my best friend's experience when riding home on his new motorcycle. He rode onto the freeway and quickly moved into the left hand lane. His wife, following in their car, moved into the same lane a short distance behind him. To her horror, a large car/SUV (I don't recall which) then tried to move into the left hand lane into the same space occupied by her husband's motorcycle. At this part of the freeway there wasn't a shoulder on the left side of the road, only a concrete barrier. My friend's wife recalls seeing her husband beat on the door of the invading vehicle with his right hand. Evidently, the other driver never heard or recognized the source of the beating on her door (yes the driver was female), because she continued to move into the lane and rubbed my friend's motorcycle up against the cement barrier and continued on without stopping.
I keep referring to my friend's wife's version of events because my friend does not remember any of it. While he recovered fully from the accident, he's no memory of it. However, he was convinced that commuting by motorcycle was not something that was worth the risks. If you are not seen by the other drivers on the road, it sometimes does not matter how good a driver (or rider) you are nor does it matter how maneuverable your ride may be.
Not to second-guess a guy in that position, but one would think that if you have time to beat on her window, you have time to hit the brakes, move back 30 feet, and get clear altogether.
If IIHS ran the same test comparing mid size cars to SUV's the results would show the SUVs to be "safer". If the IIHS then ran the same test comparing SUVs to trucks, the trucks would come out ahead. Compare the trucks to bulldozers, and the bulldozers win. So who's first to go out and buy a Peterbuilt or Freightliner, not to mention a Caterpillar? Weight and mass always wins, but you can't allow fear to rule your life. The vast majority of drivers go through life without ever being involved in an injury producing crash.
There is one stat concerning the new small cars that is actually more interesting. vis a vis "saving the environment". Their fuel mileage is usually no better than compacts like the Civic, Corolla, or Focus. In some cases it's actually a bit lower. The Fit comes in just a tad worse than the Civic. The Yaris is the same as the Corolla. The compacts also have a lot more hood in front of the driver than the subcompacts. That gives them more "shock absorbing" than the smaller cars, in case of a crash.
The problem with O'hare's commentary is that it doesn't go far enough. As a bike commuter, he poses a threat to me in his economy car. Why does he need 2500 lbs to move a 180 pound body, when a carbon free 20 lb bike will do that and save money for him on that gym membership? People who argue that the safer midsize cars should be removed never take the argument far enough and a pply it to themselves. The roads would be a lot safer for cyclists if buses were the only traffic to worry about.
Better yet, why don't we just make everyone walk?
As long as they're wearing their helmets ...
The really scary part about this is that there are sites out there where this conversation wouldn't be parody.
I'm sure it is less safe to be in a small car than in an SUV when you're headed for that tree. But let's face it: the SUV is over. So the real comparison is between mid-size cars and small cars. There, the stat cited is that mid-size cars are 17% safer. That's a distinction that's pretty insignificant at the individual level -- I make few decisions based on whether they entail a risk of death that's 6 in 1 million versus 5 in 1 million. But it is meaningful at the level of public health, where a shift of, say, 30% of drivers from mid-size to subcompact cars could entail hundreds to a thousand or so extra deaths per year in traffic accidents. One logical response, then, might be to compensate with steps that push more people to take subways and trains, which have a risk of passenger death that's close to 0. Get someone to shift 10% of their trips from driving to the subway, walking or bus, and you've wiped out the higher collision risk of driving a smaller car. Overall, if higher gas prices increase public transit ridership by a few percent, that could more than compensate for the effect of people driving smaller cars, and we'd ultimately be seeing a transit system with fewer deaths. In this, as in most things, you have to look at how people's overall shifts in behavior affect public health outcomes, not just the effects of any isolated behavior.
The SUV was temporarily inconvenienced in a perfect storm of elevated fuel prices followed by a credit collapse and crippling recession. You might want to wait a couple years into the economy's recovery phase and see what consumer attitudes shift to in the presence of disposable income and more moderated fuel prices before writing that obituary.
Meanwhile, public transportation is often not an effective or convenient option in the expansive suburban layout that defines the non-core area of most US cities. You can't realize a 10% gain in public ridership unless there is currrently a 10% waste in private transportation providing low-hanging fruit for easy exchange, and that is a pretty tall assumption. Out of curiosity, I've looked into the bus routes that would serve my daily work commute and my twice-weekly family commute, all involving suburban origin and destination, and discovered that the weekly net difference is about four hours (personal car) versus fifteen (bus). And that doesn't even account for the additional uses and convenience I get from car ownership, which I might have to abandon entirely to realize any net financial savings from bus ridership.
Consequently I do not use the bus, and there is no 10% gain waiting behind the wings if I switched. To the contrary, it would be a losing proposition.
Mouse, you're misusing your percentages. You don't need a 10% gain in public ridership. What you need is a gain in public ridership that is one-tenth the size of the transfer from mid-size cars to subcompacts. Let's say 30% of mid-size car drivers shift from mid-size cars to subcompacts. Then you need a 3% rise in public transit ridership to compensate for the increase in collision-related deaths. This is all back-of-the-envelope (or worse) but that's the idea anyway.
Okay, 3% versus 10%, but how likely is that to happen? Is there a 3% transfer to public transit waiting to happen, and if so, where will it come from and why hasn't it happened already? If the source of the transfer is something transient, like the lousy economy (plausible), what happens to that 3% when the economy improves?
I recall reading last fall that high gasoline prices over the summer had already led to a 3% increase in public transit ridership. High gasoline prices would also be the factor pushing people to shift to subcompacts rather than mid-sized cars. And I'm sure that the high gasoline prices that led to a 3% increase in public transit ridership had led far fewer than 30% of midsize car owners to shift to subcompacts; so any increase in gas prices big enough to cause a shift of 30% from midsize cars to subcompacts would probably lead to a much GREATER than 3% increase in public transit ridership. So, yeah, I think such an estimate is actually pretty conservative, and that overall rising gas prices will lead to fewer traffic collision deaths, not more.
Even if we do declare that the SUV is over, you've still got the problem of minivans, whose weights are much more akin to SUVs than to small cars, and of larger pickup trucks. Demand for those vehicles is far less elastic than for SUvs in preference to midsize cars, because it's driven by factors less variable than gasoline prices.
I'm a mother of three small children, so I'm stuck with a minivan or large SUV for the next six years at a bare minimum. After that, it shifts from impossible to merely impractical -- I could possibly fit my own kids in a midsize car, but couldn't ferry any others around (forget bringing a friend home from school, having their cousins come visit, etc). Even mothers of two have problems juggling carseats and multiple children in midsize cars, which don't always accommodate rear-facing seats very well. Personally, I'll most likely continue to be a menace to subcompacts until the older children start driving their own cars in fifteen years from now.
It's easy to talk about how SUVs are wasteful and unnecessary, and in many cases it's true that it's simply a question of preference. However, there will always be significant legitimate demand for larger vehicles, so you're always going to have to factor them into road-safety calculations.
But let's face it: the SUV is over.
Where I live there are virtually no other kinds of cars on the road. People may be buying smaller cars, to the extent they're buying at all, but even if all new car buyers eschew the SUV we're stuck with the ones that are out there.
You don't need a sub-compact car to be environmentally friendly. The Accord gets 21/31 MPG, which is pretty good. The Civic gets 40/45, which is better than the Mini Cooper or the Smart Car. Essentially, buying a Smart Car or Mini Cooper is something you do because it's trendy not because it's incredible eco-friendly. I wonder if you put compact and mid-sized sedans up against SUV's if they'd perform worse or better.
Technically, the smaller vehicle with the smaller engine consumes fewer resources in the processes of production and subsists on smaller lifetime quantities of non-fuel operating fluids such as coolant and oil. Fuel economy is an important, but not final, metric if absolute environmental impact is your goal.
LOL
According to TTAC the most dangerous type of vehicles are compact pickups. In addition to not being small and light, they also tend to roll over.
http://www.thetruthaboutcars.com/the-ten-most-dangerous-cars-of-2009/#more-311695
Interestingly, the safest 10 vehicles are not SUV's, which might pause the fella above me recommending that we all drive caterpillars.
Perhaps instead of speed limits we should have momentum limits. Vehicles over certain mass limits would have to travel at lower velocities.
Point two, why isn't there a vehicle designed with more safety in mind? If you throw away the assumptions of automotive design, you should be able to design something to withstand standard head on collision forces.
If there were a standard bumper height, we could ensure that all cars have massive bumpers at the same height level, which could absorb much more crash impact.
I have the same thought on a daily basis. Why is the speed limit the same for the truck towing 30,000 pounds, the SUV with a high center of gravity and poor braking, and the sports coupe?
Regarding your point two: Volvos are built with alot of those principles in mind. For instance, the current S40 is built (IIRC) to be able to take a 45-mph front end collision with a solid object without having the engine break the firewall. I might be mushing this a bit, but my main point is: Volvo designed that S40 to take a substantial front end hit.
Regarding your point 3: Ironically, all automotive design is currently being impacted by european pedestrian safety laws. They must have a certain curve to their hood, and a certain bumper height, and allow a certain deformation of the hood where the pedestrian might hit, to help ensure minimal injury at low speeds.
Read that again: global automotive design of vehicles is being impacted to help preserve pedestrian life.
How many motorists are killed each year? Why don't we have standard bumper heights? Why is the same driver's license I get when showing my abilities in a 2800 pound FWD Civic suitable for driving a 5000 pound SUV?
This stuff doesn't make sense to me, personally.
I know one [and only one] good argument against the variability of highway speed limits based on vehicle type or driver qualifications: the uniform flow of traffic is much safer than a Maxwell-like distribution, presumably occupying a wide range between the Winnebago and the Carrera. This argument doesn't work quite as well for city roads given the stop lights and traffic density which would squeeze this distribution significantly.
incidentally, the speed limits for trucks are different in a lot of states on the interstate highway system, and even some non-interstates, for that very reason... and as much as I'd like to say that makes things safer, in a lot of ways, for cars that are going even slightly over the "car" speed limit, being stuck at the head of a pack of speeding cars when a truck, already going slowly, lurches out in front of you to pass an even slower moving one of its brethren... all it takes is for one of the cars behind you to forget to slow down/slam on their brakes and you become the leading edge of a steel wave of hurt or death.
To use the smart as an example, the passenger cell is made of a high strength steel which is basically so rigid that, when struck by another automotive, the other vehicle will deform around it
It's not just safety of the passenger cabin, but an issue of deceleration as well. Crumple zones help spread the deceleration over a longer period of time which reduces the force of impact to the occupants. A rigid steel structure will apply more deceleration force to the occupants.
I understand.
There can be advances made in regards to seat deformation and seatbelt stretch, as well as airbag inflation/deflation. You don't have crumple zones to decelerate the car, you have them to decelerate the passenger. It makes more sense to make a car with an exoskeleton of indestructibility, but a passenger seat/seatbelt/airbag that can more effectively control the deceleration of the passenger.
Instead, we have cars where minor accidents (i.e. 15-20mph side impacts on the front or rear end) cause massive amounts of damage because the car is designed to quickly break. Meanwhile, the passenger seat and seat belt are nearly identical to what they were 30 years ago. At least the air bag has gotten better...of course, plenty of people get concussions from the airbag.
To put it another way: Why are baby seats reliant on the car to crumple to avoid life-threatening G forces? Why isn't the baby seat put in a viscous fluid dish that would allow the seat to absorb some of the force without distributing it to the baby or relying on the car?
The same principle is applied in a Subaru all wheel drive system: The fluid in the differential is fine, until there are shearing forces. Then the fluid starts to solidify, transfering forces.
The concept of making the cars themselves more destructible in the pursuit of safety is akin to using poisonous chemicals to kill off cancer. It may get the job done, but at what cost?
Could we not just make large and small cars much tougher externally, and develop universally acceptable methods of distributing the forces around the passenger through revised seats, seatbelts, and airbags?
Joe
At a guess, no, we can't. For one, you'd have to completely abandon conventional car doors in favour of double doors(one for the exoskeleton, one for the endoskeleton), which would dramatically reduce mobility and cargo transferability into and out of the car. Furthermore, you'd still have things breaking in a crash, it'd just all be internal, meaning you'd have to tear the car apart to repair it all. You'd be dramatically increasing write-offs, I'd wager, not reducing them.
Fundamentally, in a crash, you need to apply a large delta-v over a very short time. Either you need some sort of shock absorber to spread that out and thus lower acceleration to survivable levels, or you kill your passengers. Since you can't go all Cheyenne Mountain and still have a car that can fit a family into a single lane of traffic, your shock absorber has to be stuff breaking to slow the deceleration. It doesn't much matter where in the car that stuff is, it'll still be expensive. That said, the dramatic increase in safety it causes is well worth it.
Alsadius covered the physics, so here's the economics: A car designed to the specifications you require is going to be as expensive as two or three cars designed to current specifications, and the supercar will still be subject to normal environmental decay and mechanical wear-out. What's the point of doing that, even if in an accident the physics didn't apply and the passenger and car would both be saved?
A side note: newer generations of cars, especially hybrids, are being equipped with low-rolling-resistance tires. Essentially, tires that create less friction when rolling and therefore allow more energy to be conserved.
The problem is that these tires have abyssmal braking distances....because they can't generate the sort of friction necessary to slow the car down AND continue rolling, to equate to a short braking distance.
Similarly, they tend to handle terribly during swerving manuevers.
So the small, light cars that don't fare well in accidents are equipped with tires that help prevent the driver from maximizing the car's already poor performance.
Sounds like a safety winner to me :)
The IIHS report is seriously deficient in a couple of ways. It compares small cars to midsize cars to reach the conclusion that more weight = better. This is not at all true (or really supported by their data). While it is true that a midsize car is safer than a small one, midsize cars are also safer than SUVs (which weigh more). Further, they make no effort to eliminate co-variables from their data. It is feasible that it is the larger structure and therefore higher energy absorbing characteristics of the crumple zones that makes it more safe, not the weight at all. It is all about the construction of the vehicle.
The statement regarding maneuverability is particularly flawed in that equates number of claims with safety. Correlation does not prove causation. It does not account for the severity of the accidents, the type of drivers prone to drive that type of car (age, income, etc), the driving conditions (urban vs rural), and a whole host of other factors.
There is also a flaw in their argument of basic physics. It is true that when two object collide, the one with more momentum will experience a less severe collision, while the lower momentum object will experience a more severe collision. But when one object is immovable (such as a tree) the higher the momentum, the more drastic the crash will be, particularly if the object is so stiff as to bounce off like a rubber ball (like a truck with a ladder frame).
The IIHS is also heavily lobbying for red-light cameras, as the increased citations will help increase insurance premiums. They are not an organization whose study results should be taken as unbiased.
I say that despite all the fine folks who work hard there.
I'm commenting a little frequently here, but here's another thought:
Small cars (like the Smart) can be, and sometimes are, made with different grades of steel.
To use the smart as an example, the passenger cell is made of a high strength steel which is basically so rigid that, when struck by another automotive, the other vehicle will deform around it.
Carmakers are doing amazing things with crumple zones, energy deflection, and using materials of different strengths to help protect passengers.
Just remember that high strength steel that remains lightweight tends to be very expensive.
So you can ride in a lightweight car that is made out of high strenght steel, but it'll cost you money.
Or you can ride in a lightweight car with less high strength steel, and it'll cost you safety.
Or you can ride in a heavy car that didn't cost as much.
Emissions? Safety? Cost?
Pick any two.
Joe
You don't have crumple zones to decelerate the car, you have them to decelerate the passenger. It makes more sense to make a car with an exoskeleton of indestructibility, but a passenger seat/seatbelt/airbag that can more effectively control the deceleration of the passenger.
Your Volvo's, BMW, Mercedes, VW already come with seat belt pretensioners (which cinch the seatbelts race car tight when a collison is detected) and force limiters (which limit the force the seatbelts can apply to the occupant) to limit injuries. The problem is, if you set the force limiters on the setbealt to be able to deal with a crash in a car with no crumple zones, there isn't enough space for the driver to move forward before impacting the inside of the vehicle.
You need both crumple zones and seatbelts/airbags to deal with the crash forces.
For example - if you had no crumple zones and you impacted a fixed barrier at 45mph you would only have 18" with which to decelerate the occupant from 45mph to 0. That's not enough room - you need part of that deceleration to be absorbed by the crumpe zones - or the forces applied by the seatbelts/airbags would be too high and the occupant would be injured.
Jmo - That's my point. Is there no other way to increase the passenger's deceleration capacity? Perhaps a steering column that collapses inwards when the airbag deploys, providing an extra 6 inches of room? A seat that deforms or changes shape in some manner to provide additional room?
A broader seat belt to spread the force of deceleration over a wider contact patch of the body?
I'm not trying to be ignorant to assume the safety engineers have not already walked through all this. But I'm curious as to if there are not better ways.
Perhaps a steering column that collapses inwards when the airbag deploys, providing an extra 6 inches of room?
Collapsable steering columns have been standard equipment since the late 1960's.
TreeJoe,
Also, take a look at this: http://www.youtube.com/watch?v=vBl22idhC2s
Look at how far forward the driver is allowed to move forward even when the maximum seatbelt and airbag force is being applied. The amount of deceleration that would have to be applied would rise substantially without the crumple zones.
Crumple zones are the only practical engineering solution.
I understand there are collapsible steering columns since before the mass produced airbag, but I don't believe they move inwards when the airbag deploys. Am I wrong?
As far as crumple zones being the only practical engineering solution, I'll believe that when pigs fly :)
TreeJoe - why do you assume that you can come up with a better safety design than hundreds of thousands of man-years of automotive engineers trying to improve trillions of dollars of business? If they haven't come up with a better way, I'd say it's likely that none exists - there'll be the occasional way that's better by some narrow criterion, but none that makes a better car.
TreeJoe, human bodies don't respond well to sudden deceleration, nor can the safety engineers know exactly what kind of accident the vehicle is going to suffer. It might be a 20mph jaunt into a light pole while attempting to navigate a corner on a city street, it might be a 40+40mph combined head-on crash on a side road, it might be drifting off an interstate due to drowsiness, overcorrecting, and then rolling four times before being struck by another vehicle. The car is nothing more than a metal machine, both expendable and replaceable, while the contents of the machine are a human life. Your callous focus on saving the machine and assuming the human life inside will have to put up with whatever is left is...odd.
The other problem is that very few accidents will bring a car to a dead stop -- whatever it runs into is probably damageable. If the car takes none of the force in failing, then it will go through the object it strikes like a 3500-pound cannonball. You're complaining about a car suffering hundreds of dollars of damage in a small accident, but that can be the difference between injuring and killing a pedestrian, or a bicyclist, or a motorcyclist, or plowing through the front thirty feet of the local deli after an accident that would have stopped a normal car in five. And if the driver is unconcious or lifeless either as a cause or result of the accident, it's best that the car take damage, shed drivetrain parts, and ultimately stop. That's the ultimate deadman's switch, regardless of what other mechanisms might fail.
What is it you are trying to achieve? The machine is expendable and replaceable.
Meghan,
First of all, it's good to know that someone as tall as you can fit into a Mini Cooper. Good to know if I'm looking at one of those (I'm just a couple inches shorter than you).
Second, this is another great argument for more public transportation. You don't hear about too many subways crashing.
As the leasor for two SUVs and two minivans (sequentially, not all at once), I need to take exception to the characterization of all SUV/minivan owners as "reckless" and "self-indulgent."
My wife and I have two young children (ages 9 and 6). When they were very young, the number of federally mandated large, bulky items we were required to carry around with us when we travelled with our kids (car seat, stroller, baby carrier, diaper bag, etc., etc.) necessitated the storage space of at least a minivan if not an SUV. And, given my wife's height (4', 9") and her tendency to throw out her back, a traditional trunk would have put her in traction from lifting the stroller in & out after just a few months.
I'm not saying we're all that typical, but the larger point is this: there are legitimate uses for SUV's and minivans.
In the meanwhile, I think I'll keep working on being a safe driver, regardless of what size car I'm driving...
TreeJoe,
I understand there are collapsible steering columns since before the mass produced airbag, but I don't believe they move inwards when the airbag deploys. Am I wrong?
Yes, you are. To quote Volvo re: the 2009 S60 "Volvo S60 safety features include a collapsible steering column, dual-stage airbags for the driver and front passenger, a side-impact protection system..." That being said, the steering column only moves backwards when the forces applied to it exceed a certain threshold.
As far as crumple zones being the only practical engineering solution, I'll believe that when pigs fly :)
The key word is practical. For example, any technology would need to be able to protect a 95th percentile man as well as a 5th percentile woman.
As far as crumple zones being the only practical engineering solution, I'll believe that when pigs fly :)
I'm sure you'll find that the reported figures are not corrected for the proportion of women drivers of the smaller cars, nor for the lower IQs and spatial abilities of those drivers.
Larry S.
Unless you drive like Jason Bourne, you can't completely avoid the idiocy of other drivers. Every time I drive a prius from zipcar, I drive accepting the fact that despite my best efforts, a drunken driver can crumple my car like a beer can, and that all struck prii drivers are prime nominees for the darwin awards.
EB,
The Pruis has a 5 star crash test rating - what are you talking about?
From the IIHS:
"Injury measures — Measures taken from the dummy indicate a low risk of any significant injuries in a crash of this severity. Head accelerations from the B-pillar and roof rail hits were low."
I drive a '78 town car so in the event of a crash the newer compact is my crumple zone.On a serious note though,how are drivers in small cars able to relax? I drove to Toronto today in my wife's Hyundai Accent,and I feel lucky to still be here writing. Was so stressed out from the constant fear of dying,I can't tell you. Will never do it again.
Some of you on here drive small cars. How do put that feeling in the back of your mind...or can you?