Relevance of IIHS crashworthiness ratings

[new6ton]

Newton's first law does not care which car is stationary and which car is moving at 60mph. The result of the collision either way is that both cars lose 30mph (for equal mass cars) and the person gets ejected at 30mph relative to the car.

Imagine both the person and car moving at 60mph. If the car suddenly stops, his body continues to move at 60mph ejecting him out of the windshield. But I haven't seen or read a stationary car with person inside being hit and got ejected outside the windshield. Please show some news items regarding this if I just haven't come across them.

Most people I know don't have curtain airbags. Since it's not possible to retrofit cars for these. Then what to do with millions and millions of cars without curtain airbags. These are only available in top variants or top model like the 2019 Fort Ecosport Titanium 1.5L. Most buys the Fort Ecosport Trend 1.5L without any curtain airbags. Can't a world body make all new cars manufactured everywhere in the world requiring curtain airbags or make them mandatory?

 

[russ_watters]

Imagine both the person and car moving at 60mph. If the car suddenly stops, his body continues to move at 60mph ejecting him out of the windshield.

Yeah, I get it - but how is that different from starting stationary and suddenly accelerating to -60mph? In both cases the car subtracted 60 mph.

But I haven't seen or read a stationary car with person inside being hit and got ejected outside the windshield. Please show some news items regarding this if I just haven't come across them.

I doubt it is a common scenario, so I'm not sure I would have much luck with that.

 

[berkeman]

But I haven't seen or read a stationary car with person inside being hit and got ejected outside the windshield.

The issue usually comes about when people don't wear their seatbelt. If all of the windows are rolled up and don't break in the collision, they just bounce around inside the vehicle and break lots of stuff (including their neck). If a window is open (like on the hot Sunday evening), they often get ejected and optionally run over.

Bottom line -- always wear your seatbelt!

 

[new6ton]

Yes, seatbelt is very vital. That is why airbag is called SRS or Supplemental Restraint System.

However, seatbelt can't prevent the head from colliding with the sides during T-bone or side collision. Here curtain airbag prevents that.

For millions and millions of cars without possibility of curtain airbags. Is it better for the side windows (made of tempered glasses) to have film or tint that can prevent it from breaking into pieces or is bare windows better? See the actual tests:

 

[new6ton]

I was asking whether tint or film in windows have an adverse effect during T-bone or side collision is because outside the United States, many countries have cars with totally dark tint at daytime. 99% of cars have tint so it's like there is a film to the tempered glass side windows. This is the typical traffic outside the US:

Not only do you have to struggle with very dark tint in your car with poor visibility at night. You have to struggle with container truck and fuel truck racing with you. I once had a professor whose car was squeezed between two containers and he died.

Ironically, outside the United States where curtain airbags is most important. It is only an optional choice and not available in many cars even 2019 models. This is why there are hundreds of death daily in many countries. What saved it is the super traffic that can take you 3 hours to just travel 7 miles (less chance of strong collision because of very slow speed).

 

[berkeman]

For millions and millions of cars without possibility of curtain airbags. Is it better for the side windows (made of tempered glasses) to have film or tint that can prevent it from breaking into pieces or is bare windows better?

In my experience, the film on the side windows would have no useful effect on ejections or injuries from broken side window glass.

The side windows break into small cubes that do not cause lacerations for the most part. And any plastic film will not provide any strengthening of the window against ejection.

 

[OCR]

And any plastic film will not provide any strengthening of the window against ejection.

✔

And any plastic film could "somewhat hold" the small cubes in place, and contribute to

more lacerations. . .?

.

 

[cjl]

The side windows break into small cubes that do not cause lacerations for the most part. And any plastic film will not provide any strengthening of the window against ejection.

It's definitely possible to have a plastic film that would strengthen the window. Ordinary window tint wouldn't though - you'd need something more akin to a security film used in home security, or the film used in the laminated glass in car windshields.

 

[berkeman]

It's definitely possible to have a plastic film that would strengthen the window. Ordinary window tint wouldn't though - you'd need something more akin to a security film used in home security, or the film used in the laminated glass in car windshields.

But please don't make the side windows as strong as the front windshield and the rear window. There's an important reason that the side windows are not made to that strength standard. They don't need to be, and making them that strong would make it much harder for EMS to access occupants in the vehicle. Just wear your dang seatbelts folks, and yes, upgrade to side impact airbag equipped vehicles when it works for you.

 

[cjl]

But please don't make the side windows as strong as the front windshield and the rear window. There's an important reason that the side windows are not made to that strength standard. They don't need to be, and making them that strong would make it much harder for EMS to access occupants in the vehicle. Just wear your dang seatbelts folks, and yes, upgrade to side impact airbag equipped vehicles when it works for you.

There's an interesting question though about safety there - sure, it'd make EMS's life more difficult, but it would also decrease the chance of getting ejected or having a limb severely injured after the window breaks in a rollover or the like. It's also not clear that your statement is true - many modern higher end vehicles from brands known for safety have started to go towards using laminated side glass, including Audi, Volvo, Mercedes, and Subaru. A (likely incomplete) list can be found at the end of the AAA report here.

 

[berkeman]

I guess I need to read up on that. So I will need to carry a fire axe now for side window access instead of my trusty EMS window punch?

 

[cjl]

At least if you're dealing with one of those newer cars, yes. Many of them appear to only be laminating front windows though, so if you find yourself in a situation where you can't get through the front, try the rears (or even the back window - those frequently are not laminated either)

 

[berkeman]

A (likely incomplete) list can be found at the end of the AAA report here.

Rhut-rho...

Key Findings: All of the selected vehicle escape tools successfully cut through the seat belt material on all attempts. However, two tools performed significantly worse than the others during seat belt cutting tests, averaging 13.5 and 23.0 seconds to cut through the belt. The remaining four tools each averaged less than 2.5 seconds. In glass-breaking tests, four of the six tools were successful in breaking the tempered glass. Two of the tools, however, failed to break through the tempered glass (the type most commonly used for vehicle side windows). None of the tools were able to successfully break the laminated glass, which stayed structurally intact even after being cracked. The research indicates that it is nearly impossible to break through laminated windows withoutspecialized equipment.

So it's not just harder for EMS to gain access, it's harder for the occupants of the vehicle to self-extract after an accident. Hmm...

 

[cjl]

So it's not just harder for EMS to gain access, it's harder for the occupants of the vehicle to self-extract after an accident. Hmm...

Yes, but you have to balance that against the reduction in injury and death caused by the lower chance of ejecting the occupants, as well as the ability to better contain limbs and body parts during a rollover. If the window breaks away easily, it's also very easy for your arm to end up getting crushed by the car during a rollover if it ends up going outside of the window. It's a balancing act between ease of rescue after the fact vs maximum protection during the accident. I haven't seen enough data to know which one ends up being safer overall.

 

[jack action]

Yes, seatbelt is very vital. That is why airbag is called SRS or Supplemental Restraint System.

However, seatbelt can't prevent the head from colliding with the sides during T-bone or side collision. Here curtain airbag prevents that.

For millions and millions of cars without possibility of curtain airbags. Is it better for the side windows (made of tempered glasses) to have film or tint that can prevent it from breaking into pieces or is bare windows better?

A very easy-to-apply safety measure to compensate for the lack of curtain airbags is wearing a helmet.

 

[berkeman]

Yes, but you have to balance that against the reduction in injury and death caused by the lower chance of ejecting the occupants, as well as the ability to better contain limbs and body parts during a rollover.

You don't get ejected if you are lawfully wearing your seatbelt. And I have been in high speed rollover accidents (well just one thankfully). Hold onto the steering wheel or your seatbelt or the door handles. Your arms will not flail out the windows.

 

[cjl]

Not everyone does that though, and crash safety is designed around what actually happens, not what should happen. There's a reason racecars use window netting, for example.

 

[OCR]

A very easy-to-apply safety measure to compensate for the lack of curtain airbags is wearing a helmet.

Jack, your comment deserves more than a simple like. . . because it's so very true. This might be just a little off topic, but it certainly relates to the helmet issue. . .

On October 9, 2007, at 2:40 PM, HFEO #1 succumbed to his injuries at San Jose Regional Medical Center. His fatal injury was from a single violent impact to the head from blunt force trauma.

Heavy Fire Equipment Operator #1 was a man named Matt Will . . . it's possible he

might have survived, had he been wearing a crash helmet. . . ?
This is a 24 page PDF report about the incident. . . I remember it well. .

California Department of Forestry - 2007-10-08-matt-will-final.pdf

.