Here is a real old versus new car crash that is rare. The 2021 Corolla and the 1992-1996 Camry 4 cylinder have almost the exact same curb weight of 2930 and 2910 pounds. Usually crash tests show a newer vehicle that is not only newer but also several hundred pounds heavier.
Both men in the Camry survived without serious injuries. Not sure about the optional passenger airbag. The Camry has a powerful 1st generation airbag. The kind that is designed to protect an adult man at over 35 MPH with no seatbelt. This requirement was repealed in 1998 due to severe injuries from airbags in minor accidents. The intrusion in to the driver’s area in the Camry appears to be significant, so this powerful airbag had to have been crucial to prevent injuries from bottoming out the airbag and hitting the steering wheel in this severe accident.
This shows the problem with old cars versus new cars. The newer cars are stronger and use the older weaker car as the crumple zone to absorb energy. The speed of this crash wouldn’t have had to be much more for the driver of the Camry to be crushed. The injuries for the front seated occupants were significant in the Corolla, so it would have only been worse if it had hit another late model car. So when a newer stronger car hits another newer stronger car, things are somewhat back to where we started.
The good news is the 1997 Camry is still a good car, it’s a little bit heavier, and its front end structure is probably 1.2 to 1.3x as strong as the previous generation. That’s probably why it had the lowest fatality rate of all full size cars in the 1998 statistics that I posted about in a different thread!
I think it’s best to avoid driving any car that is under 3000 pounds and has an IIHS structure and safety cage rating that’s any less than Good if you drive on non divided highways a lot.
The best safety device is good driving, nobody gets killed in a crash that did not happen. Cars are safer then ever before and yet we keep killing more people because of lousy driving.
Does that include seat belt use? If you were to isolate the belted crash fatalities from the rest of the deaths per mile statistics which include non belted drivers, the data from 1975 to 2022 would be much different. The creation of the interstate highway system significantly reduced the number of high speed head on crashes which has a major impact on that statistic.
Your graph ends in 2017, with 1.16 deaths per 100 million miles. It continues down to 1.10 in 2019. Then it jumps up to 1.34 in 2020 and remains close to that through 2022, which is the greatest increase ever! Of course this isn’t due to vehicle safety, it’s due to driver behavior.
Surely you jest. “Safer driving” means always wearing your seat belt, always paying 100% attention to your surroundings and to the operation of your motor vehicle. It means keeping your phone put away, and not dialing/texting/looking at websites while you are driving. It means driving defensively, and never assuming that oncoming traffic will stop just because you have the green light or right-of-way. It means resisting the temptation to drive aggressively or give in to “road rage”.
For example, the car I drive most often is a 2002 Daewoo Lanos. Even by the safety standards of its day, this car had a “poor” safety rating. By today’s standards, it would be considered a death trap.
However, I have kept this car very safe, by doing the things listed above. When the light turns green, or I get the left turn arrow, I always wait to see that all lanes of incoming traffic have stopped before proceeding. At a 4-way stop sign, traffic circle, or other similar arrangement, I always drive courteously and safely. Now, could a big SUV careen across the median and hit my Daewoo, making the car fold up like a soda can? Sure, such a thing could happen, just like a bridge or overpass could collapse, or an asteroid could fall from the sky. However, the majority of accidents which I see are caused by driver inattentiveness, driving aggressively, and failing to stop for traffic signals, etc. And those are all things which we should be able to avoid.
+1
Here is a graphic example of someone who is either simply a very bad driver, or who is excessively aggressive when he is behind the wheel. This is a totally avoidable crash that only happened because of the boneheaded behavior of the person who was driving this RV:
I don’t remember the numbers but a substantial number of deaths among the young are being thrown out of the car with no seat belts on. Then of course dui and with legalized pot will get worse and they like to talk speed and inattentive driving. I’ve pulled apart the numbers before and think there was a little bias in the statistics toward programs being pushed.
The rv slide on its side and onto its roof. Didn’t even complete I full revolution. The rv collapsed like a big pillow. And trucker with cam didn’t even try to slow down. Rv drivers are amateur clowns. A trucker is a pro.
Just how fast do you think 80,000 lbs slows down ?
tractor-trailer weighing 80,000 pounds traveling under ideal conditions at a speed of 65 miles per hour will take 525 feet to stop (almost the length of two football fields).
A feather and a rock will fall at the same speed in a vacuum. Same with a loaded versus empty truck, if the brakes are strong enough. But they get away with having weaker brakes for some reason. There is a law for tractor trailer stopping distance, and it was put in place decades ago. But I believe the law is somewhat permissive of having weaker brakes. It must be cheaper. Otherwise there wouldn’t be much difference between a car and a tractor trailer in stopping.
Now most train brakes are as you imply. The maximum braking force is limited to what is needed to stop an empty rail car without letting the wheels slip. It takes a loaded train a long time to stop.
Agreed, there is no way 80,000 pounds will stop as fast as 20,000 pounds… I don’t care if you take a car with 6 piston Brembo brakes on the front and 4 piston on the rear, about the best stopping force out there, if you double the weight or triple the weight it will take longer to slow the car down…
I have driving a lot of trucks and pulling trailers as well as sling tow trucks including box trucks with a GVWR of 32,000 pounds and they all stopped way better empty then loaded…
The more weight something has to it the longer the stopping distance…
Almost all your exotic cars all have the best of the best brakes but yet they have different stopping distances…
For outstanding heat management and longevity, the Charger SRT Hellcat Widebody features standard 15.4-inch Brembo two-piece front brake rotors with six-piston front calipers and four-piston rear calipers. Stopping distance is four feet shorter (107 feet ) from 60-0 mph
The Porsche 911 GT3 RS and the Chevy Corvette Z06 both needed less than 100 feet of pavement to come to a halt
The biggest difference is the Hellcat is about a 1,000 pound heavier…
I think there is a rule in physics covering this. Mass times something or other times something or other force equals etc, etc. A 20 pound bowing ball will be harder to stop than a tennis ball. But I’m not a physician. I think newton had something to do with it. But I’m into economics and business not physics. Seems like common sense and our pinewood cars usually won, until those St. Paul boys obviously cheated, or had engineers for dads.
Yes, heavier cars are harder to stop because of inertia . In fact, how hard something is to stop is basically the definition of inertia. Inertia is a property of matter, so the more matter (weight), the more inertia, and the harder the car is to stop.
There’s two different but related terms, momentum and inertia. Momentum equals mass * velocity. A change in momentum is associated with a corresponding force. The bowling ball hits the wall and stop, there’s a brief but big force on the wall. The formula often said to be Newton’s second law, Force = mass * acceleration, actually isn’t. Newton never said that. But F = m* a is roughly the same thing as saying a change in momentum is associated with a force, which IS what Newton said. A bowling ball, having more mass, has more momentum than a tennis ball at the same speed. The bowling ball would impart more force to the wall of the two.
Inertia is roughly the amount of energy needed to stop something that is moving. It takes more energy to stop a moving bowling ball than a tennis ball, so the bowl ball has more inertia. Inertia isn’t the same as momentum, inertia refers to the mass, not the speed. The energy needed to effect the stop (of something moving in a straight line) is proportional to mass * velocity^2. For things that move in a straight line, mass is usually the term used, not inertia.
For things that rotate, inertia is the more common term, I = moment of inertia. The energy of something that rotates is I * w^2, w is the angular speed of rotation (w is similar to rpm).
A car that rolls down a hill, at the end of the hill it has both kinds of inertia, the car is moving in a straight line and the wheels are rotating .
One of my favorites in the engineering field is prof Steven ressler from West Point. But he loses me with all his formulas. I guess you concur that it takes more to stop an 80,000 pound truck than an empty one. Don’t get in their way.
