NHTSA says "Don't make small vehicles lighter"!

National Highway Traffic Safety Administration (NHTSA) says "Don't make small vehicles lighter"!



http://www.autonews.com/news.cms?newsId=6683

quote:

“Cutting vehicle weights across the board would make vehicles even more unsafe than previously thought. But reducing the weights of the larger light trucks on the roads would have little effect and could lead to fewer highway deaths overall.

These are key conclusions of a highly anticipated federal study of the safety effects of reducing vehicle weights. Made public Tuesday, it updates a 1997 study, also by the National Highway Traffic Safety Administration. And it is certain to be fodder for upcoming debates about how to change corporate average fuel economy standards, or CAFE, after the 2007 model year. CAFE rules are set until then. “

It's nice to see that the Federal Government finally caught up with Newtonian physics....

FORCE = mass*acceleration

ENERGY = 1/2*velocity^2

My only hope now is that they finally realize the world is a sphere and not flat.

Originally posted by PacerX
[B]
ENERGY = 1/2*velocity^2
[B]

Dont forget to add your mass in there. :p

KE = .5mv^2 ;)

Originally posted by Steve0
Dont forget to add your mass in there. :p

KE = .5mv^2 ;)

I thought e = mc^2?

:D

Originally posted by johnsocal


But reducing the weights of the larger light trucks on the roads would have little effect and could lead to fewer highway deaths overall.



That makes be feel even better when a logging truck is glued to my back bumper. It doesn't occur to any of these geniuses that people buy Ford Super Duties as commuter vehicles because they don't like being eye-level with the wheel hubs of a semi.

Maybe we should all stop being afraid of the soccer mom in the Suburban.:confused:

This is what helped the Clinton administration keep the safety nuts at bay when they were pushing for higher CAFE standards about 6 years ago, before they turned attention to SUVs.

Government is generally neutral. Unfortunately it's the very loud very small fringe group of people that stir up the pot. Sometimes for great things, but not here.

The first point they're missing is the effect of mass on the handling and braking of a vehicle. All things being equal, a heavier vehicle will not stop as fast nor be as nimble as a lighter vehicle. Therefore, by advocating heavier vehicles, they are increasing the chance that a given vehicle will be in an accident.

The second point is that weight is relative. If every vehicle weighs 6000 lbs then it's a draw. It's kind of like standing out of your seat at a baseball game: you only get a better view until everyone else does it too, then you're all equal again. On a moral level, I find it to be a very selfish decision when someone buys 6000 lb vehicle thinking it's "safer", because their extra safety is completely at the expense of whoever they hit. Add that to the increased chance they have of hitting something, and buying heavy vehicles becomes an increasingly irresponsible decision.

You know, I think a good lawyer using that reasoning could have some luck suing SUV drivers that are involved in accidents:
Lawyer: "Ms Jones, why did you buy that Excursion"
Ms. Jones: "Because it was safe"
Lawyer: "Why is it safe"
Ms. Jones: "Because it is so big"
Laywer: "Do you know anything about physics, Ms. Jones ...."

Originally posted by R377
The first point they're missing is the effect of mass on the handling and braking of a vehicle. All things being equal, a heavier vehicle will not stop as fast nor be as nimble as a lighter vehicle. Therefore, by advocating heavier vehicles, they are increasing the chance that a given vehicle will be in an accident.

This is wrong.

Year in and year out, the safest vehicles in deaths per 1,000,000 miles driven are large, heavy sedans.... not nimble little sports cars.



Originally posted by R377
On a moral level, I find it to be a very selfish decision when someone buys 6000 lb vehicle thinking it's "safer", because their extra safety is completely at the expense of whoever they hit.

First, keep your morality out of my garage, especially when it flies in the face of easily deduced physical facts.

Second, larger vehicles are not only safer in 2 (or more...) vehicle accidents, but they are also safer in accidents that involve hitting things other than other vehicles.

Third, if you buy a little car because you want the rest of the world to be safer, I feel no responsibity whatsoever if I accidentally run your a$$ over with a K3500 Diesel. You made a choice, and it was a dumb one at that.

Fourth, my primary responsibility in this life is to health, safety and welfare of my family. Yours is to your family. I'll handle mine, you take care of yours. I would invite you not to compromise their safety on a set of fatally flawed assumptions.


Originally posted by R377
Add that to the increased chance they have of hitting something, and buying heavy vehicles becomes an increasingly irresponsible decision.

See above.

I'm not responsible for you. If you buy a Yugo and get killed in an accident with a 1959 Cadillac Eldorado, I call that natural selection.


Originally posted by R377
You know, I think a good lawyer using that reasoning could have some luck suing SUV drivers that are involved in accidents:
Lawyer: "Ms Jones, why did you buy that Excursion"
Ms. Jones: "Because it was safe"
Lawyer: "Why is it safe"
Ms. Jones: "Because it is so big"
Laywer: "Do you know anything about physics, Ms. Jones ...."

And I will be happy to be the expert rebuttal witness who will re-educate this misguided liberal arts major attorney relative to impact physics.

Ms. Jones is right, Newton says so, Einstein says so, and so does everyone who knows anything about vehicle engineering.

Pacer,

I would like to respectfully say that you missed his point. If you are driving a K3500 diesel and you hit me while i am driving a k3500 Diesel then the weight issue has nothing do with safety. You are only safer in you K3500 if you hit a Yugo. Thats what he meant by making yourself safer at the expense of others.

Chris

Nope, I got his point, it's just wrong.

Let's take two K3500 diesels and smash them into each other at 30 mph. Given the equation Energy = 1/2*mass*velocity^2, we very quickly see that due to the fact that velocity is the squared component and the effect of mass is halved, impact energy goes up radically for velocity, but not too much for mass.

Now, here's a simple rule of thumb for a body...

For any body with a given frontal area, an increase in one component of frontal area increases volume BY THE SQUARE of the value changed. Like this:

10*10*10=1000, 11*10*10=1100 (1100-1000=100, which equals 10^2)
50*50*50=125,000, 51*50*50=127,500 (127,500-125,000=2500, which equals 50^2)

Did you follow that?

The best approximation for crush area in a car (we're using rules of thumb here to keep things simple) is the volume of that area up front. The bigger vehicle has, by definition, more impact area. Greater impact area = more volume to crush, which means more energy can be traded off for deformation in an impact.

Now... follow this...

Two K3500's crashing into each other have VASTLY more volume to crush than two Cavaliers do. The only trade-off against that is the actual amount of energy to be dissipated within that volume, which only went up by a factor of 1/2 (1/2*mass in the energy equation).

This also indicates a very basic problem with the insurance industry using an offset frontal crash to validate vehicle safety:

To do well in an offset frontal crash, you have to stiffen the area that is going to be impacted. When you do that, you automatically bias the vehicle against doing as well in the Federal Government's full frontal crash testing. The two specifications fight each other. To make one better, I sacrifice performance in the other.

GM's tack has been to do well in the Federal Testing to the detriment of the insurance testing. Toyota has generally done the opposite.


To sum up:

Larger, heavier vehicles are inherently safer than small, light vehicles simply due to the fact that they are larger and heavier.

Lets make a Cavalier w/ a K3500 front end :)

Yeah... a Cavalier Z71.

Something interesting (sort of follows what Pacer was saying):

"Large four-door passenger cars had the lowest death rates, followed closely by minivans. Small, four-door cars had the highest fatality rates, with mid-size SUVs and compact pickups second.

In certain types of crashes, pickups and SUVs are equal to or better than cars in terms of safety. But the possibility of a rollover crash makes an SUV more dangerous overall than a similarly-sized car.

NHTSA found that mid-size SUVs weighing on average 4,022 pounds are nine times as likely to roll over than large cars weighing 3,596 pounds, and were twice as likely to kill an occupant of another vehicle. "

http://www.detnews.com/2003/autosinsider/0310/15/b01-298332.htm

The article covers the same story, but is a bit more detailed.

Originally posted by PacerX
This is wrong.

Year in and year out, the safest vehicles in deaths per 1,000,000 miles driven are large, heavy sedans.... not nimble little sports cars.

You are using one small statistic to prove your point? I was talking accidents, not just deaths. Deaths represent but a tiny fraction of all accidents recorded on public highways. And I'm not denying that you're more likely to survive an accident behind the helm of a F-350 than you are a Chevette.

Also you need to factor in driving habits when touting accident statistics because we all know drivers of sports cars are more reckless than soccer moms in Caravans, and that has nothing to do with the capabilites of the vehicle itself.

Originally posted by PacerX
First, keep your morality out of my garage, especially when it flies in the face of easily deduced physical facts.

Second, larger vehicles are not only safer in 2 (or more...) vehicle accidents, but they are also safer in accidents that involve hitting things other than other vehicles.

Only if whatever they hit can move. Doesn't do much good against bridge abutments, falling off cliffs, into rock cuts, etc.

Originally posted by PacerX
Third, if you buy a little car because you want the rest of the world to be safer, I feel no responsibity whatsoever if I accidentally run your a$$ over with a K3500 Diesel. You made a choice, and it was a dumb one at that.

Fourth, my primary responsibility in this life is to health, safety and welfare of my family. Yours is to your family. I'll handle mine, you take care of yours. I would invite you not to compromise their safety on a set of fatally flawed assumptions.

Jesus christ, Pacer, do you have to take every post that opposes your views personally :rolleyes:? We're talking theory here, okay? I have no desire to get into one of your pissing matches.

But on your fourth point. I will say it's an incredibly selfish stance when a person puts their own good above everyone else's, especially for little reason. Most societies have advanced a little beyond that.

Originally posted by PacerX
And I will be happy to be the expert rebuttal witness who will re-educate this misguided liberal arts major attorney relative to impact physics.

Ms. Jones is right, Newton says so, Einstein says so, and so does everyone who knows anything about vehicle engineering.

Yes, I know, you are Boss Kettering reincarnate.

Again, I'm not saying she's wrong when she thinks she's more likely to survive an accident. But what I am saying is she made a conscious choice to do something for no other reason than to increase the chance of harming someone else versus her own perception of safety.

Buy hey, it was a tongue-in-cheek comment and I'm no lawyer (and certainly not a liberal arts major). I just thought it was an interesting possibility. Maybe we'll see it on an NBC movie of the week.

FWIW, I'm not in any way advocating limiting people's choice of vehicles. If you need a F350 because you haul horses then that makes sense. I'm just saying people who buy the biggest thing out there just because they think it's safe, well there's flawed reasoning and questionable ethics behind their choice.

Originally posted by R377
...
Again, I'm not saying she's wrong when she thinks she's more likely to survive an accident. But what I am saying is she made a conscious choice to do something for no other reason than to increase the chance of harming someone else versus her own perception of safety...


No she isn't trying to increase the chance of harming someone else she is trying to increase her chance of not being harmed. BTW being selfish is why we are all here, Natural Selection-Survival of the Fittest. Call it whatever you want but we are here as we are because of the sometimes selfish actions of our ancestors. It ain't right to call someone selfish because they wish to protect themselves.;)

Originally posted by 91_z28_4me
No she isn't trying to increase the chance of harming someone else she is trying to increase her chance of not being harmed. BTW being selfish is why we are all here, Natural Selection-Survival of the Fittest. Call it whatever you want but we are here as we are because of the sometimes selfish actions of our ancestors. It ain't right to call someone selfish because they wish to protect themselves.;)

I kinda worded it that way on purpose. She obviously isn't thinking she's increasing the risk of harm to other people, but she is.

Everyone comes to their own answer when trying to balance their own good versus the good of others. Where you place your flag defines your morality.

Here's an analogy. Lets say I hate walking on crowded city streets. So I buy a pitbull to protect me. Hey, I'm just doing what it takes to protect me and my family from some undefined dangers! So what if my pitbull attacks other people? That's their tough luck, they should also buy pitbulls to protect themselves.

Picked the wrong topic to bring up with me: "Pitbulls". I owned for 13 wonderful years a dog most would call a "Pitbull". He was an American Staffishire Terrier, a verified show breed registered with the American Kennel Club. They are an awesome breed, with the first of which being the original Petey from the Little Rascals, who are extremely loyal and who are very fond of children. Now this dog never hurt anyone who didn't try to attack him, only one other dog (a Chow) tried and my dog was only 6 months old and note he did not kill it. What you see is a weapon capable of tearing a mans arm off or clamping on a bulls throat and killing it within minutes. Yes this is all true my dog COULD do all that but he didn't. A dog isn't a weapon just like a vehicle isn't a weapon unless it is used like one.


I get sick and tired of people blaming a dog attack on a "Pittbull." German Shepards, and other large powerful dogs, are responsible for just as many dog bites as "Pittbulls" are and you don't hear those making national coverage, but as soon as you say "Pitbull" people start to spread the word.


P.S. -My dogs neck was 22" around and his head where his biting muscles were was 24" around and he stood 23.5" at the shoulders. The worst would he ever gave me was when his fat but sat on my leg to get his necked rubbed. I will always remember that dog he was like another brother to me (goodbye El Diablo Hombre).

Originally posted by R377
You are using one small statistic to prove your point? I was talking accidents, not just deaths. Deaths represent but a tiny fraction of all accidents recorded on public highways.

So... deaths per million miles is a small statistic.

I'll make a note.


Originally posted by R377
And I'm not denying that you're more likely to survive an accident behind the helm of a F-350 than you are a Chevette.

You're more likely to survive an accident in a Cadillac DeVille than you are a Volkswagon Passat or a Nissan passenger car.... ask yourself "why"? Starting to see the point? Mass and crush space are tied for #2 in the "most important safety feature" department after seat belts.



Originally posted by R377
Also you need to factor in driving habits when touting accident statistics because we all know drivers of sports cars are more reckless than soccer moms in Caravans, and that has nothing to do with the capabilites of the vehicle itself.

1) You can't provide data.

2) The suitability of a vehicle to protect occupants in an accident is in no way dependant on driving habits. It is a purely technical issue.


Originally posted by R377
Only if whatever they hit can move. Doesn't do much good against bridge abutments, falling off cliffs, into rock cuts, etc.

Wrong. Crush space is the #1 issue in hitting a rigid body. Were you paying attention?



Originally posted by R377
Jesus christ, Pacer, do you have to take every post that opposes your views personally :rolleyes:? We're talking theory here, okay?

Ummmm... you're talking hypotheses, I'm talking theory. There's a difference.

Second, you attempted to claim the moral high ground by stating that folks who drove large and heavy vehicles were irresponsibly endangering those around them.

I happen to believe that folks who drive small vehicles are irresponsibly endangering themselves and their loved ones/passengers and aren't too bright since the physics is easy to understand. "Self-evident" might be a better word.


Originally posted by R377
I have no desire to get into one of your pissing matches.

This is no pissing war, you're unarmed.

All you have behind your point is the hysterical blatherings of media mouthpieces and semi-retarded car magazine writers coupled with a flawed understanding of the physical model of vehicle impact dynamics. You've chosen to have a technical argument with a degreed engineer with 12 years of experience in safety systems in various parts of literally millions of automobiles, and then... to top it off... you attempted to make it an issue of MORALITY.

Now, I can keep this as civil as the next guy, but let's drop the morality argument right now.


Originally posted by R377
But on your fourth point. I will say it's an incredibly selfish stance when a person puts their own good above everyone else's, especially for little reason.

If the fact that me strapping my children into a +4000lbs. vehicle offends you... well, I was going to apologize... but that doesn't make any sense.

IF the size of my vehicle protects my children and happens to kill someone who wasn't smart enough to buy a safe (i.e. BIG) car, so be it.


Originally posted by R377
Most societies have advanced a little beyond that.

Thankfully, ours has not. You are your responsibility. Not mine.



Originally posted by R377
Yes, I know, you are Boss Kettering reincarnate.

I have no desire to have an exceptionally expensive private engineering college named after me.

A night school would be nice... but I don't see it happening.


Originally posted by R377
But what I am saying is she made a conscious choice to do something for no other reason than to increase the chance of harming someone else versus her own perception of safety.

So, when did you aquire the ability to divine people's intentions? Did the thought ever occur to you that her reasoning may simply be that the vehicle makes her and her own safer?

When did you become the arbiter of morality? Why is it somehow morally less desireable to buy the safest vehicle possible to protect those who you are responsible for?


Originally posted by R377
FWIW, I'm not in any way advocating limiting people's choice of vehicles.

Right. You're just saying it is morally reprehensible to buy a large vehicle to protect your family.

Gotcha.


Originally posted by R377
If you need a F350 because you haul horses then that makes sense.

How about I just buy a K3500 because I want it? WHY I want to buy it, or the purpose in owning it, is quite simply none of your darned business, so take you holier-than-thou judgementalism elsewhere.

YOU will NOT dictate what vehicle I choose to buy, for WHATEVER reason I choose to buy it. IF I want to buy it because I simply like massive vehicles, that's my entirely personal choice - and neither you or Arianna Huffington are going to stop me.


Originally posted by R377
I'm just saying people who buy the biggest thing out there just because they think it's safe, well there's flawed reasoning and questionable ethics behind their choice.

1) The reasoning is NOT flawed, the data backs it up. Fork over data.

2) Your view of ethics is the only thing I see that is questionable here.

all i have to say is....NO DUH!!!!! why do you think them rich folk drive all dim 6000lb suv's?

Originally posted by R377

Also you need to factor in driving habits when touting accident statistics because we all know drivers of sports cars are more reckless than soccer moms in Caravans, and that has nothing to do with the capabilites of the vehicle itself.


i'd say moms in minivans are more dangerous.
you ever see one of them behind the wheel?!;) :D

Originally posted by PacerX
I happen to believe that folks who drive small vehicles are irresponsibly endangering themselves and their loved ones/passengers and aren't too bright since the physics is easy to understand. "Self-evident" might be a better word.


This is exactly why I hope market forces eventually make it painful to own an SUV. I don't think this kind of selfish attitude is going to go away.

I really don't feel like I should have to buy a 7,000lb SUV and waste all the extra nonrenewable resources associated with manufacturing it, owning it, and retiring it at the end of it's life. I would also like to reduce dependance on mid-east oil and decrease the odds that my children will have to fight in a war there.

Sure, I care about safety for my family, but I'd rather do it with non-selfish safety enhancements that don't come at the expense of others. Some that help me: Airbags, Side Airbags, Door Beams, Reinforced Roofs, Antilock brakes Traction Control and other things. and some that help both me and others: Like Stability Control.

Forget about small cars. I'd like to feel safe in a 3500lb car.

I think we should all drive M2 Bradley Fighting Vehicles. It's nine seat capacity is very handy for carpoolers and soccer moms. And safety is it's middle name...with it's welded aluminum and composite armor. An applique supplemental armored tile system is optional. :)

Sure..at 25 tons it's abit hefty, but it's 600 horse turbo-diesel moves it out pretty smartly.

At any rate...no sense taking chances....just clear a swath through traffic with 200 rounds per minute of high explosive or armor piercing rounds from the turret mounted 25 mm "Bushmaster" chain gun . Two, ready to fire, TOW missiles (not including reloads) are also provided for those real jerkwads. I just wish it came in more colors, other than just olive drab and desert sand though.


Why would anyone want to bother with those puney, wimpy, fullsized SUV's?

This is exactly why I hope market forces eventually make it painful to own an SUV. I don't think this kind of selfish attitude is going to go away. Ditto that. I'm beginning to find the "I gotsta gets me mine" attitude quite loathsome. I'm not suggesting that we sit in a circle, roll a fat one, and sing Kumbaya, but a little courtesy for your fellow man now and then would be great.

But, the best defense is a great offense, right?:rolleyes:

Originally posted by PacerX
Third, if you buy a little car because you want the rest of the world to be safer, I feel no responsibity whatsoever if I accidentally run your a$$ over with a K3500 Diesel. You made a choice, and it was a dumb one at that.


Originally posted by PacerX
I happen to believe that folks who drive small vehicles are irresponsibly endangering themselves and their loved ones/passengers and aren't too bright since the physics is easy to understand. "Self-evident" might be a better word.

IF the size of my vehicle protects my children and happens to kill someone who wasn't smart enough to buy a safe (i.e. BIG) car, so be it.

Just a quick question....Are you a sadistic person?

I think R377 is looking at it this way, why should the rest of the world be forced into buying big trucks/SUVs to protect themselves (...and their families) just because 100 million soccer moms think their big truck is safer while unintentionally endangering the lives of everyone around them?

Its much like the situation w/ guns. You have a weapon that can kill fairly easily but is suppose to protect you. If these fall into the wrong hands, then we have a problem.

I'm sure Mrs. Jones is only getting her SUV for good intentions, but shes putting others around her in a hell of a lot more danger than she would have if she just bought a full-size car. At least thats what the facts of statistics tells us....

I read an article about this..and at the end, it made a good point.. This study didn't take in consderation about safety designs..


I guess if I had baby, my favorite gut pick for safety would be to put the child right in the middle of a Suburban or HD crew cab truck.. But also, I'd make sure that I'd drive it appriately for its size and weight, and not get myself distracted..

It irks me when I see parents take their eyes off the road to take care of their baby in the back seat...


Personally, my 2nd vehicle choice will either be a truck or a mid to full sized car.. 2500HD if I plan to use it to occasionally haul my future toys around (but would be a pain to drive around)... or a 94-96 Impala SS (always wanted one).. or a Sub Legacy Sedan with turbo (assuming it comes to the US, and its roomy enough).. or whatever other mid-full sized sedan that goes for $25k..