Crash Testing

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heylinb4nz

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#171589 24-Apr-2015 10:11

The new ACC levies got me thinking about crash testing and ANCAP ratings.

When you look at the speeds they test cars (24-60kmh) they are not even close to real world speeds. Mere fender benders vs actual serious crash.

Why don't they include an offset head on at 200 kmh which is real world head on crash. Or pole at 60 kmh instead of 24 kmh (I dont know of any cars that can get sideways at 24 kmh).

I have always suspected that these ANCAP ratings are less to do about safety and more about auto makers duping people into buying newer (supposedly safer) cars.

These ACC levy discounts may very well be propaganda to boost new cars sales.

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#1290675 24-Apr-2015 10:50

2 vehicles having a head on at 100km each does not equal a 200kmh crash. If the vehicles are identical mass then it's simply a 100-0 deceleration for each vehicle. Exactly the same as hitting an immovable obstacle at 100. If the opposing vehicle is of greater mass then yes the severity of deceleration is higher for the lighter vehicle. The only way it can be a 200kmh crash severity for a vehicle travelling at 100kmh is if the opposing vehicle is infinitely heavier which of course is impossible, but getting close if you ride your pushbike at 100kmh into a 50T road train doing 100kmh.

Edit: I started my post with "sorry", which makes me sound condescending. There's enough condescending prattle around here, I just wanted to point out the physics, not try to demean anyone. Sorry.

MikeB4

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#1290679 24-Apr-2015 10:55

I believe that ANCAP is based on international standards. It makes sense that they use up to 60KM/h as I would guess that research has shown that the vast majority of motor vehicles globally seldom get above 60km/h. Also if a vehicle is totalled at 60 it is a very
good indicator of what it would be like at 100km/h.

Wade

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#1290694 24-Apr-2015 11:07

In a lot of cases people start to take evasive actions such as heavy braking, cars go into slides etc all scrubbing speed off original speed so having a car sliding sideways into a solid object at 20kph is quite probable

I would personally never buy less than a 5 star rated car, when i watch the news and there is a fatality, nine times out of ten the death occurs in the older/lower safety rated car, and that is evidential enough for me to form an opinion

heylinb4nz

656 posts

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#1290699 24-Apr-2015 11:10

1eStar: 2 vehicles having a head on at 100km each does not equal a 200kmh crash. If the vehicles are identical mass then it's simply a 100-0 deceleration for each vehicle. Exactly the same as hitting an immovable obstacle at 100. If the opposing vehicle is of greater mass then yes the severity of deceleration is higher for the lighter vehicle. The only way it can be a 200kmh crash severity for a vehicle travelling at 100kmh is if the opposing vehicle is infinitely heavier which of course is impossible, but getting close if you ride your pushbike at 100kmh into a 50T road train doing 100kmh.

Edit: I started my post with "sorry", which makes me sound condescending. There's enough condescending prattle around here, I just wanted to point out the physics, not try to demean anyone. Sorry.

Interesting found an explaination

http://physics.stackexchange.com/questions/45578/is-two-cars-colliding-at-50mph-the-same-as-one-car-colliding-into-a-wall-at-100

heylinb4nz

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#1290701 24-Apr-2015 11:13

Wade: In a lot of cases people start to take evasive actions such as heavy braking, cars go into slides etc all scrubbing speed off original speed so having a car sliding sideways into a solid object at 20kph is quite probable

I would personally never buy less than a 5 star rated car, when i watch the news and there is a fatality, nine times out of ten the death occurs in the older/lower safety rated car, and that is evidential enough for me to form an opinion

I was first on scene for a side pole impact accident (estimated 70-80 kmh), car doing 100 kmh in the wet into a sweeping corner (residential area). Note very pretty..car was like a doughnut..the front corner of the car was nearly touching the rear corner of the car (tree right in the middle).

Needless to say the occupants were pretty messed up.

Needed counselling after witnessing that.

meesham

973 posts

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#1290713 24-Apr-2015 11:25

1eStar: 2 vehicles having a head on at 100km each does not equal a 200kmh crash. If the vehicles are identical mass then it's simply a 100-0 deceleration for each vehicle. Exactly the same as hitting an immovable obstacle at 100. If the opposing vehicle is of greater mass then yes the severity of deceleration is higher for the lighter vehicle. The only way it can be a 200kmh crash severity for a vehicle travelling at 100kmh is if the opposing vehicle is infinitely heavier which of course is impossible, but getting close if you ride your pushbike at 100kmh into a 50T road train doing 100kmh.

Edit: I started my post with "sorry", which makes me sound condescending. There's enough condescending prattle around here, I just wanted to point out the physics, not try to demean anyone. Sorry.

Mythbusters did an episode on this as Jamie has this misconception about two cars at 100km/h equalling a 200km/h crash as well, it was a good episode and worth a watch.

frankv

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#1290734 24-Apr-2015 11:52

heylinb4nz: Why don't they include ... pole at 60 kmh instead of 24 kmh (I dont know of any cars that can get sideways at 24 kmh).

Any car can get sideways at 24kph... just get it sideways at 100kph and wait for it to slow down a bit. Maybe they do the pole test at 24kph because that's close to the usual speed at which someone goes sideways into a power pole or tree? Or maybe going into it at 60kph wouldn't distinguish between the strengths of different cars -- the outcome for all of them would be "total wreck".

I have always suspected that these ANCAP ratings are less to do about safety and more about auto makers duping people into buying newer (supposedly safer) cars.

I'm sure that as soon as someone (e.g. Govt) announces a reward (more sales) in return for meeting a criterion, the immediate response is "How can I meet the criterion easiest & cheapest?". So cars get designed and built to pass ANCAP ratings, and safety improvements become incidental. It is really important that Govt criteria accurately reflect what they want to measure, rather than just something that's easy to measure.

However, I think there's no doubt that newer cars *are* safer. I've switched from a 1990 car to a 2000 model, the improvement in handling and braking is enormous. Similarly from 2000 to 2005, with ABS and electronic traction control etc.

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meesham

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#1290737 24-Apr-2015 11:58

frankv:
However, I think there's no doubt that newer cars *are* safer. I've switched from a 1990 car to a 2000 model, the improvement in handling and braking is enormous. Similarly from 2000 to 2005, with ABS and electronic traction control etc.

Here's a head on between a 1959 Chevy and 2009 model:

DravidDavid

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#1290763 24-Apr-2015 12:36

meesham:
frankv:
However, I think there's no doubt that newer cars *are* safer. I've switched from a 1990 car to a 2000 model, the improvement in handling and braking is enormous. Similarly from 2000 to 2005, with ABS and electronic traction control etc.

Here's a head on between a 1959 Chevy and 2009 model:

Amazing! I'd still take the '59 any day though ;)

I don't think the new levy system has anything to do with safety at all. My 1997 Toyota Caldina GT-T is in the group that pays the most. Yet a 2001 GT-T, which is identical in every single way, is in the second to lowest paying group.

If they based it on safety, then they would be in the same group.

Batman

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#1290764 24-Apr-2015 12:36

Because it only happens on a race track. Usually you brake if you are conscious, and brake really hard.

Secondly, no cars would pass. Ok maybe some expensive Europeans

Batman

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#1290889 24-Apr-2015 15:33

I guess if you meant why don't we crash them into the wall at 100... Well that would be interesting wouldn't it. I bet the expensive heavy euros do better than light Japanese cars ... Bcos every now and then you read about a Ferrari or a lambo spitting out live drivers from mangled wrecks

Maybe they should start by going to 80 first

Aredwood

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#1291027 24-Apr-2015 18:17

heylinb4nz: The new ACC levies got me thinking about crash testing and ANCAP ratings.

When you look at the speeds they test cars (24-60kmh) they are not even close to real world speeds. Mere fender benders vs actual serious crash.

Why don't they include an offset head on at 200 kmh which is real world head on crash. Or pole at 60 kmh instead of 24 kmh (I dont know of any cars that can get sideways at 24 kmh).

I have always suspected that these ANCAP ratings are less to do about safety and more about auto makers duping people into buying newer (supposedly safer) cars.

These ACC levy discounts may very well be propaganda to boost new cars sales.

Have a look at the crash safety rating of a Mitsibushi L300. Even the brand new ones are only 1* And they still get completely totaled in the crash test video. What's worse is alot of companies buy them for their employees to use. So in a crash the employee is disabled for life. But the boss is happy as he saved a little bit of money.

scuwp

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#1291048 24-Apr-2015 18:56

ANCAP and Euro NCAP testing has been a well established process for decades, and has maintained largely unchanged to ensure results are comparable between models. I think the problem with it now is that just about all new cars are 5 star, but I am quite sure some will still be better than others. I think its time to review the scoring to differentiate an excellent 5 star and a one that perhaps scraped in by the skin of its teeth.

Lazy is such an ugly word, I prefer to call it selective participation

1eStar

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#1291049 24-Apr-2015 18:56

This Smart car youtube clip explains near the end that although the vehicle survives the crash reasonably at 70Mph that a human body can't handle that sort of deceleration.

Youtube link

blakamin

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#1291070 24-Apr-2015 19:32

1eStar: This Smart car youtube clip explains near the end that although the vehicle survives the crash reasonably at 70Mph that a human body can't handle that sort of deceleration.

Youtube link

LMAO.. that steering column didn't quite "get out of the way".

I'll stick to my 95 BMW 740iL.

Big bonnet! :D

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