Tag Archives: collisions

A good car to have a crash in…? Part 4

2 Mar

This is the final part in this mini – series on how to choose a car that can save your life.

If you haven’t read parts 1, 2 and 3 then I suggest you do before reading this so that you can make better sense of the points raised in this particular post.

The latest figures released for America and Western Europe suggest that the cars we drive on the road are approximately ten years old on average. Personally, I am surprised to read this. I would have thought that the ‘average’ would have been younger – closer to seven. However, I simply cannot find data that contradicts this claim and so I shall have to accept it.

A good car to have a crash in is one that will maximise our chances of survival and minimise our chances of becoming “KSI” – Killed or Seriously Injured.

At this point, we can all imagine in our minds a few particular cars that we might choose to be in, solidly manufactured by makers who have a long and proven reputation for collision safety research and who build large and well-upholstered cars. ‘Large’ cars? No – hang on – we are already becoming confused.  Just because it is large does not mean that it better protects us from KSI. Yes, it may be scientifically correct that a large car is likely to better survive a collision with a small car, but large cars do not necessarily save us from being KSI. Ask Princess Diana.

We have to look carefully now at a whole range of factors and ‘values’ to understand how to make the best choice.  If “large cars from reputable manufacturers” are good to have a crash in, three questions immediately pop up:

1) Will manufacturers or insurance companies reveal KSI data for these cars?    Answer: No.

2) Is it easier to quickly alter the direction of travel of a large car compared to a small car?  Answer: No.

3) If both large and small cars are driven at 100 kph into an unmovable concrete block, is KSI data identical?  Answer: Yes.

To find out what is really going on with modern cars and to make an informed choice, we must go back and look again at the three ‘interested parties’ involved in a collision: The Car – The Occupants – The Investigation. I call this: “The Facebook Triangle”;  each player has an opposing self-interest. Let me explain it to you.

The car manufacturer works hard to build a car with a low KSI factor, including safety by design, by build quality and by product testing.  In the real world we live in, the manufacturer will only go so far before the budget dictates that they release the car on to the market.

The crash investigator visits cars that have been involved in KSI collisions and tries hard to establish what  factors caused the KSI result. Although the investigator may see obvious reasons for KSI that were not actually  to do with the car itself, for example – a 100 ton tree falling on the car when it was stationary, the investigator will still have to attribute a KSI cause – “car roof structural integrity failure”.

The driver and passengers of the car unintentionally became involved in a collision. Effectively – if we are accurate – the driver ran out of ways of avoiding the collision and therefore became involved. The driver now hopes that the car will protect them as a last resort.

There are three players involved: the manufacturer, the investigator, the driver. All three have totally different aims. The manufacturer is trying to avoid having KSI data attached to its product, the investigator has to attach a cause of KSI to the product. Lastly, the driver (or their surviving relatives) is hoping that the cause of KSI is not attributed to the driver.

By accepting the above scenario, we can see a greater truth emerging:

A mass-produced, affordable commuter car will attract more KSI “hits” than an expensive luxury car simply on the basis that it is generally driven for more miles, driven by a more diverse range of drivers, driven in more diverse circumstances.

So, manufacturers of large luxury cars do not want to reveal accurate KSI data because it might actually show that, mile for mile in the real world, that precise model of car has similar or more KSI hits than a competitor’s standard ‘budget’ car. Manufacturers of standard ‘budget’ cars don’t want to discuss KSI openly for fear that their product gets unfairly associated with a high KSI. We can see their point because many more unskilled or otherwise dangerous drivers will drive their product instead of an expensive luxury car.

Collision investigators have to attribute a cause of KSI. If they keep writing down “…I don’t know but, jeez, the driver was completely like spaghetti once he’d been passed through all the round dials on the dashboard…” they are only hanging on to their jobs by their fingertips. Accuracy is key.

And then, there is the driver. We drivers come in all shapes and sizes and skill levels. The collision investigator and the manufacturer want to ask us – in all seriousness – “…could you have avoided that collision?…”  We rarely answer “Yes.” When looking at KSI data, it is often difficult to separate out the acts of the driver from the behavior of the car. For example, did a car leave the road because it has poor road-holding or handling characteristics or else did the driver fail to use the car’s controls correctly?

Several popular manufacturers currently have cars on the road which, technically speaking, have fatally flawed handling characteristics.

More truth emerges: Insurance companies sift through the data of KSI. They have close access to that accurate data. Do they reveal the accurate, dissected data? Absolutely not. It is competitively sensitive. However, they do often put pressure on manufacturers to improve their products. They sometimes do this quite bluntly by telling the manufacturer to improve a particular car or else the insurer will effectively “kill it off” by use of high insurance premiums.

Conversely, the ‘People Carrier’ design of car emerged partly because insurance companies noted a new KSI trend: where two vehicles collided and one vehicle had its occupants seated higher than the centre of gravity of the other, (say, a conventional car) much of the collision shock passed underneath them. The obvious flaw in this initial advantage was that it canceled itself out if all vehicles were designed in that same way and it also raised the centre of gravity, increasing the chance of the People Carrier turning over.

To find out which car is good to have a crash in, we have to run all the data backwards. Instead of looking at all the shiny cars we have available to us and then wondering which one to drive, we must imagine each one already crashed and stationary, its occupants still inside. By doing so, stark realities become clear that were previously obscure.

All cars perform worse as more occupants and luggage are added to them. Regardless of size, if the car is carrying maximum occupants and maximum luggage, that luggage and those occupants increase the distance needed to stop or evade, increase the kinetic energy that has to be dissipated in the collision, reduce the interior space available to act as a ‘free zone’ where there are no obstructions.

All humans become KSI if their internal organs are subject to an impact above approximately 27mph. When we watch film of cars being crash tested, we see how the manufacturer tries to solve this problem by making the car’s passenger compartment slow down ‘progressively’. This is done  by transferring the impact forces away from the compartment and ‘soaking up’ as much force as possible in the parts of the car that are outside the passenger compartment – the engine compartment and the luggage compartment in particular. These areas are particularly used to make impact shocks to the passengers become more softened.

Airbags and flexible interior trim add more shock-reduction still, so the more of them one has, the better overall. They convert those sudden shocks and impacts into a series of more gradual ones. That passenger compartment has to keep it’s integrity, leaving the passengers with room to move inside it as the actual impact takes place. So, a sophisticated manufacturer can turn a crash at above 30mph into a series of decelerations, each one lower than 25mph, the g-forces dissipated as much as possible within the time frame of the collision.

Drivers and occupants often survive high-speed crashes because their car actually is involved in a series of collisions within that one event and each individual impact is lower than 25mph. For example, suffering a tyre failure at 100mph (lose 10mph), bounce off the railing (lose 15mph), skid diagonally across three lanes (lose 20mph), bounce off a truck (lose 20mph), bounce backwards into another vehicle (lose 20mph) and then skid to a halt (the final 15mph). Far better than hitting one item at 100mph.

Since the vast majority of crashes are head on, it is wise to design the front of a car so that it sequentially changes shape during an accident, altering the onward course of the car. This is best illustrated by looking at a Formula 1 racing car. Notice how the driver sits in a narrow canoe-like pod with a pointed nose? What would happen if two racing cars were to collide head on? The two passenger compartments would slide past each other, decelerating more slowly over a longer time period as  ‘sacrificial’ parts – front wheels and suspension – take the brunt of the forces. Clever stuff.

So some newer cars have their mechanical components angled such that they will fold inwards and downwards, reducing the chance of the vehicle stopping dead or becoming interlocked with another vehicle. Their suspension and wheels will progressively shear off as forces rise, their passenger doors will interlock with their door frames to provide a continuous structure instead of acting as a separate panel.

Walking among the lines of crashed cars in a recovery yard, I became aware that one category of car rarely appeared: the car with four new tyres. It was disproportionately absent. I checked this with my calculator and this car was under-represented by a factor of 75% in a yard made up of 175 cars. Those “missing” cars were not there in the yard because they had managed to stop in time or else swerved to avoid the crash.

Think on that. They never actually got involved in the crash. The crash never happened.

“A good car to have a crash in…?” has been a series of articles intended to help you make informed decisions and good risk assessment. In real life, a good car to have a crash in is a two to three year old medium-sized or large car from a reputable manufacturer, carrying a five-star (maximum) safety rating. Its occupants are average build, seated and belted correctly and relaxing as the airbags explode to meet them.

A good car to avoid having a crash in?  Well, that is a different question!

A good car to have a crash in…? Part 3 – READER DISCRETION ADVISED

17 Feb

While researching this article, I have had to make some difficult editorial decisions. I refer you, dear reader, back to that very first Roadwax post which sets out my broad views about censorship.

Regrettably, I cannot tell you what I believe you should know without including some facts that may distress some readers. I do not wish to make this article appear as a ‘wise owl’ plod through statistics, farmed from reports and topped with a few vague suggestions. This is not a cut-and-paste job for a Sunday magazine. It is a genuine attempt by me to help keep my readers alive by having them empowered through their understanding of a serious issue.

Although I believe that children who are old enough to read should be old enough to also learn how to keep themselves safe, this post is not suitable for kids.

I am also stating here and now that you can skip this article and read the forthcoming “Part 4” and still benefit from a greater  understanding of how to choose a safe car. If you continue beyond this paragraph, please understand that some factual data below is distressing to read. I do not wish to sensationalize, I wish to put clarity in your mind.

On average five people get killed on British roads each day and almost sixty get “KSI” – killed or seriously injured. Deaths and injuries are declining but only by fractions of a percent and there are many complicating factors involved in dissecting even the simplest statistics on the Department for Transport website.

Other countries across the world have their own figure but one point is common to all countries: the KSI figure is unacceptably high and needs to be seen as a tragic and traumatic reminder of the human cost of mechanizing one’s population.

At this point, let us put aside how and why we crash. Being drunk, on drugs, distracted or losing control of your car or your judgement are examples that explain ‘how’ and ‘why’. Being caught in the path of somebody else who ticks any of those boxes may also make you an innocent victim.

Let us instead look at what happens in a crash.

We are all familiar with the Crash Test Dummy. These are replicas of humans, adjustable and modifiable to imitate how a human’s  body will most likely behave in a collision. Early ‘dummies’ were recently deceased corpses and even living volunteers but now these sophisticated replicas do the work.

We can watch hundreds of hours of YouTube film that shows us cars colliding with scientifically measured objects and we see what happens to the dummies. Other uploaded films show real-life collisions captured on camera and the effects on real humans. We must now make sense of what we see because there is almost no explanation attached to the footage we watch and this is itself unhelpful.

Each “crash” involves three “collisions”. The first is the car hitting an object and slowing sharply. The second collision is the passenger being hit by the g-force of slowing down, hitting the restraint systems or interior of the car. The third collision is the internal organs of the human passenger colliding with the retaining skin, skull and rib-cage of their body.

Now, we can see the limitations of the Crash Test Dummy. Researchers have to pre-load mathematical values into the crash data of a dummy because a dummy does not have a living brain or living organs.

Collision data gathered from real life crashes is far more valuable than might be expected.

A co-worker of mine called Dave once lost control of his Mercedes van and monumentally stuffed it into a wall, backwards. He was treated at the scene for shock, cuts and bruises by paramedics and again later on at hospital. He was released from hospital but collapsed within hours. Nobody had noticed a tiny, bloodless hole among his bruises. The ball point pen which he had left on the ledge below the speedometer had been launched backwards towards him during the crash. As his body twisted sideways the pen entered below his armpit, between the ribs, punctured his lung and then exited as his arm swung back and removed it. The pen was later found down by the pedals, thinly coated with the fluids from inside his body.

He recovered and returned to work. The rest of us spent our time debating furiously and fruitlessly over the safest place for a pen to be placed in our van’s cab. We eventually gave up and put them back…on the ledge…below the speedometer. Put it in the glove box? The glove box lid from Dave’s Mercedes was never found so we crossed that idea off the list early on in the debate.

This startling randomeness of real-life crash data evokes a behavioral response among emergency personnel involved in routinely attending serious collisions. It becomes necessary to cope with the unimaginable, the tragic and the completely insane world they encounter. Working with an established vehicle recovery operator, my own life changed forever. My daily contact with grieving and traumatized relatives and witnesses, handling body parts of the recently deceased, helping the Police and agencies reconstruct the last moments and cause of death of a stranger all taught me so much.

Two lessons that we discovered were deeply uncomfortable but also most enlightening.

Regardless of the car that the person drives, be it safe or unsafe, the advances in medical paramedic skills have significantly increased collision victims’ survival rates. More people’s lives are saved by prompt paramedic skill on the scene than ever before and this improves the survival statistics. One extreme example is the simplest way of linking this first fact to the next one. I have removed ‘identifiers’ from this following true story. It will make you think.

A woman was driving her medium sized car to work at 30mph on a wet road. Coming towards her round the bend was a 3 ton van, driving at 50mph. The male driver slid wide on the bend and the two vehicles met, directly and symmetrically head-on. The impact pushed the car 60 feet backwards down the road.

Paramedics and Police were on the scene almost immediately. The driver of the van was under the influence of alcohol, cocaine and cannabis. He had bruising and minor cuts. The female driver of the car was alive and sober. As the collision became inevitable, she had pushed both feet hard to the brake and clutch pedals. As the collision impact compressed the cabin in front of her, her hip bones had dislocated and her legs had traveled upwards, outside her rib cage but beneath her skin.

Paramedics were able to sustain her but she died later in hospital. Her survival that far illustrates the astonishing support for life that can now be deployed.

This account illustrates the second fact. Given the extreme but short-lived forces involved in many collisions, occupants of a car often reduce injury to themselves if their bodies are relaxed at the time of impact. If their body muscles are relaxed, they often escape greater injury when excessive force is applied to limbs and torso. Obviously, the unique and complex events of each collision involve many factors. However, it was apparent from our own empirical data as a business that drunk and therefore relaxed drivers were “walking away” from their heavily crushed vehicles more often than drivers who were sober and tense as they crashed in similar circumstances.

If, as either a car passenger or a driver, you realise that you are about to collide unavoidably with an object, you may decide to serve your body well by relaxing and making like a Crash Test Dummy.

© 2012 Loop Withers Roadwax.com

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