Why is not road safety treated the same way as aviation safety ?

[Ixion]

Air travel is about the safest form of travel there is. But the whole approach to aviation safety is totally different to that to road safety.

Imagine if air accidents invoked the same response as road accidents.

If an air accident (or even an incident) happens, an independant team of investigators will go to work, not to establish blame , or find someone to give a ticket to, but to objectively and scientifically determine WHY the accident occured.

They assume that nobody WANTS to crash, so if an accident happened it was because something went wrong. Equipment failure? Procedural defect? Human error ? and why? Fatigue? Inadequate training? etc .Once they have determined the cause(s) they formulate responses to prevent such accidents in the future .

How very different to road accidents, where a policeman conducts a cursory investigation, directed not at finding the cause (because that is invariably assigned as either speed or alcohol ) but rather to gather evidence to charge someone with something. So long as a prosecution results, noone cares if anything is done to prevent future accidents.

What if air accident investigation followed the same process ?

Pilot Officer Prune brings the 747 in to land too fast, on a wet runway in the dark. P O Prune qualified on 747s 30 years ago (easy enough, its only a scratch and win test and a half hour observed flight), but until today has only flown Cessnas. He hasn't had any briefing on 747s but vaguely remembers someone telling him the approach speed (though he's got it wrong). The control tower is unmanned, the government decided to save some money. Half the runway lights don't work, and there are some big potholes in the runway.

P O Prune does his best in the landing , but he's 50 knots too fast. One wheel hits a pothole , the plane slews, P O Prune jams on the brakes (no-one ever taught him how to deal with emergencies, his whole training was only 10 hours long) ; a wheel locks in the wet, the plane slews and leaves the runway, and clips a building. Several people are injured , one seriously.

A policeman arrives to investiagte. he determines that P O Prune was not drunk, and that therefore the crash must be caused by excessive speed. He charges P O Prune with dangerous flying, and he loses his licence. The police call for an immediate reduction of in flight aircraft speeds to a maximum of 200 knots.

Absurd, isnt it. yet's that's EXACTLY how we approach road accidents.

Is it not time that the repsonsibility for accident investigation (and determining who if anyone should be prosecuted) was removed form the police. They don't take it seriously, and do a piss poor job of it. An independant Road Accident Investigation department might make a big difference.

(Cross posted to the Safeas forum)

[candor]

Gooooood post. They are now deleting - everyone be aware. Today I find my slightly sarcy post questioning if the speed poll relate to over limit or excess for conditions (as after a 9mill advert campaign am not sure yet what sped means) has disappeared. So they are in defense mode. New need for subtlety damnit. So take care posting - be safeas or we won't "see ya there!:bye: "

[Skyryder]

There is an organisation set up for this but they do not investigate road accidents. The Transport Accident Investigation Commision, TAIC. There is no reason why this Crown Agency could not do what Ixion suggests. It would show impartiality and their findings could be used for prosecution by the Police should the need arise. Of course this is not going to happen due to the poor quality of New Zealand roads and the possible conflict of interest with the aims and goals of the Government's ROAD SAFETY STRATERGY 2010.

http://www.ltsa.govt.nz/strategy-2010/

SKYRYDER

[Motu]

Blame...blame something,blame someone - this country is set up to appoint blame.Not just Police and officials,but by the very population! Soon as something happens our first response is to make sure we can't be implicated by blameing someone or something else.No one will ever step up to the plate and say - ''I fucked up,it's all my fault.''

Until we can change the mindset of the Nation we haven't got a hope in hell of changing policy.

[Jantar]

If anything this aviation based philosophy should be taken a step further. In aviation, pilots are encouraged to report ALL incidents,not just accidents. This means that all pilots can learn from mistakes made by others. No prosecutions can result from this self reporting, but any lessons learnt are passed on.

In road safety it is just the opposite. Our poice have a blame mentality. If something has gone wrong, then someone is to blame and a prosecution must be laid. Even if nothing has gone wrong, but someone has broken an artificial rule, then that person is penalised.

We could see a big improvement in traffic safety by moving away from the blame and penalise system, to a report and learn one.

[marty]

i guess it comes down to economies of scale. i work in the aviation industry, and fly planes, and have a fair bit of experience in serious road crash investigation, so i guess i have a fair insight.

every aircraft incident is (supposed to be) reportd - near misses, airspace incursions, overruns, dings etc. each is investigated by a small team of experienced aviators.

i guess that is where the basis of the culture starts, unlike minor m/v crashes that go unreported/uninvestigated, leading to a more of an ambulance at the bottom mentality.

[Swoop]

I'm involved in an aviation safety review at the moment. Unfortunately the same approach to road safety is being applied by CAA. Find someone who can easily take the blame - and then hammer that person.

[Jantar]

I'm involved in an aviation safety review at the moment. Unfortunately the same approach to road safety is being applied by CAA. Find someone who can easily take the blame - and then hammer that person.
I hope that review is looking at a ground based company or person, and not flight crew. I'd hate to see our reporting system get compromised by arse covering.

[Swoop]

I hope that review is looking at a ground based company or person, and not flight crew. I'd hate to see our reporting system get compromised by arse covering.
Approx 25% ground and 75% air.
I haven't held comments back so far.

Too many egos involved with aviation.

[idb]

Yeah, I've never quite figured out why someone always has to be charged.
A friend of mine's 16 year old daughter was riding her scooter to work one morning when she rode up the back of a parked dark-coloured car.
She was carted off in an ambulance, scooter (bought new) was written off, she was off work with broken bits for six weeks and is only now back on light duties.
I apportion no blame to anyone here - sometimes shit happens.
The cops have charged her with reckless or dangerous something or other.

Now, the poor chick has rooted her bike, wrecked herself and lost considerable income - now they want to make sure she gets a conviction that will affect her future insurance premiums and excesses.

The point escapes me somehow.

[marty]

one main reason for the depth of investigation is that many aviation accidents result in a death, and therefore the matter needs to be investigated back, to eliminate/prove the cause of death, or if you like, the cause of the crash. aircraft engineers are often held responsible for an aircraft failure, and if blame can be apportioned, then it will be. the checks and balances for an LAME is much greater than it is for an A grade mechanic, in fact the 2 jobs cannot be compared. i have worked with both - i am an LAME - and most auto mechs that i have seen turning their hands to aircraft are, frankly, cringeworthy.

for the last 10 or so years every fatal car crash has been investigated as a homicide in the first instance, although there is significant public pressure (esp in auckland) to not close down fatal car crash scenes for more than 2 hours, even though often a day is needed to investigate a scene that may cover 100m, 2 or 3 bodies, and any number of vehicles. how long does it take to do a scene investigation? have a look and see how long a house/school/park is closed off for when a dead body is found. that is how long a road would need to be closed to do it properly.

it is an accepted risk of driving that you may be involved in an accident, however people percieve that they can get into a plane and it arrive safetly without hitting anything. change the accepted risk, change the attitude to prevention rather than reaction

[sAsLEX]

i am LAME

Might pay to use the full meanign before throwing the acronym out there

Lead Aircraft Maintanence Engineer is my guess

[Titanium]

How many hours and how many $ to get a PPL or even go solo? vs how many hours and how many $ to get a car licence?

When I was a widdle air force cadet..... I could fly a plane before I could drive a car.

Not sure what I mean but......

[Finn]

Blame...blame something,blame someone - this country is set up to appoint blame.Not just Police and officials,but by the very population! Soon as something happens our first response is to make sure we can't be implicated by blameing someone or something else.No one will ever step up to the plate and say - ''I fucked up,it's all my fault.''

Until we can change the mindset of the Nation we haven't got a hope in hell of changing policy.

You are absolutely right Motu.

But I still think you're a ignorant grease monkey on many other issues.

[Jantar]

In 37 years of aviation (1 more than motorcycling) I have self reported 3 incidents. In 2 cases I was pilot in command, although not pilot at the controls when the incident first developed. In one of these cases, an incipient spin from 250 feet, I was able to take control quickly enough to keep it as an incident (otherwise I wouldn't be typing this now), the other one did result in a heavy landing causing damage. In the 3rd incident I was CFI and had authourised a student flight that almost went horribly wrong.

In each of these cases, if the aviation world worked the same way as the police do things with traffic, I would have been charged with some offence, so would not have reported any of these. In aviation though, I did report them, and because of one of these incidents, along with a similar one that did result in a fatal at Drury, the flight manual for one type of aircraft has been changed.

So rather than punishing someone, future loss of life can now be avoided.

[marty]

Licenced Aicraft Maintennance Engineer.

and about $8-$10k, 50 hrs flying for a good quality PPL.

$80-$100, no driving, for a drivers licence.

[Skyryder]

Blame...blame something,blame someone - this country is set up to appoint blame.Not just Police and officials,but by the very population! Soon as something happens our first response is to make sure we can't be implicated by blameing someone or something else.No one will ever step up to the plate and say - ''I fucked up,it's all my fault.''

Until we can change the mindset of the Nation we haven't got a hope in hell of changing policy.

So what's the alternitive. The Cave Creek inquiry springs to mind. And look how many deaths and injuries that accident caused where no one was held responsible.

Accidents are caused by human error. Not all errors can be foreseen but when they can and loss of life occurs through negligence, unsafe practices, cheap economy etc. then a prosecution should take place.

But I see your point. Unfortunately no one in their right mind is going to admit guilt if there is a chance to get themselves off.


Skyryder

[RabidTraNZiT]

Isn't there a portion of the PPL (well all Pilots licenses really) called 'human factors'? Perhaps we should look at a similar thing for road users. Anything that raises awareness of all the risks, and not just the easy-to-pigeonhole ones, has gotta be a good thing for every road user.

Marty - could you pls explain the human factors thing for us, (it was explained to me some time ago and i'm prolly a bit rusty on it). Cheers :sunny:

[MacD]

Gooooood post. They are now deleting - everyone be aware. Today I find my slightly sarcy post questioning if the speed poll relate to over limit or excess for conditions (as after a 9mill advert campaign am not sure yet what sped means) has disappeared. So they are in defense mode. New need for subtlety damnit. So take care posting - be safeas or we won't "see ya there!:bye: "

The old LTSA website had a series of pages relating to accident statistics and average vehicle speeds. They defined (in a footnote) "speeding" as "excessive speed for the conditions" not "exceeding the speed limit" . I'm not sure if the new LTNZ pages have anything similar?

Actually I just found the new page:
Ministry of Transport - Speed (http://www.transport.govt.nz/speed/)

I suspect the line between "speeding" and "exceeding the speed limit" is far too often blurred when discussing the cause of road accidents. The emphasis on not breaking the speed limit lulls the Mabel's (TM - Ixion) of this world into thinking that as long as they are not breaking the speed limit they are "safe", no matter how badly they are driving otherwise. The converse of such a simplistic approach was seen in the "Killer" adverts of last year.

[Kickaha]

Imagine if air accidents invoked the same response as road accidents.


If road accidents could potentialy kill as many people at one time as a aviation accident they probably would

[marty]

you could do a phd on human factors, but the basis of recognising that an accident is imminent often is traced back to a manufacturing attitude or design, maintennance attitudes, pilot attitudes. a common reference in human factors is that of slices of swiss cheese. each hole represents a risk behaviour/attitude/fault. lay them on top of each other, and chances are the holes won't line up. MOST of the time they won't. the one time they do though, is when the risk is at its greatest, and the incident is most likely to happen.
http://www.aviation.unsw.edu.au/about/articles/swisscheese.html

[Lou Girardin]

o

for the last 10 or so years every fatal car crash has been investigated as a homicide in the first instance,
This policy was introduced as a result of a seriously stuffed up Police investigation of a triple fatality in Southland. The Police blamed the driver of the car in which all three died.
A subsequent private investigation found that the investigation was inept and their conclusions were wrong. It was accepted that the driver of the other car was responsible. He was charged and convicted.
In a fit of pique, Police 'management' the said that all fatals would now be treated as homicides. Even clear cut, single vehicle accidents would result in major road closures and damn the public inconvienience.

[Skyryder]

What is the point of having a police force if they do not investigate? thats like saying we should get "independant" detectives to investigate crime??

I'm not jumping on Lou's response here but there is one hell of a difference between investigating a crime and a fatal vehicle crash. If the police treat every fatal accident as a potental homicide one could argue on that basis that they should also treat 'all' deaths as potential homicides.

TAIC is an idependant investigation unit Of the Ministry of Transport and investigate Air, Rail, and Maritime accidents. There is no reason that this unit could not investigate road and vehicle fatalities.

Personaly I believe that the role of the HP has been subverted from serving the public to one of producing the desired results of Government policy.

Skyryder

[Ixion]

,,
What is the point of having a police force if they do not ivestigate? thats like saying we should get "independant" detectives to investigate crime??

And there you state the problem. The police investigation teams approach the crash investigation on the basis that they are investigating a crime. The whole focus is on "who do we blame, who do we charge" And as soon as they have someone they can charge, their investigation is done. Civil aviation investigations ask, not "who can we blame" but "what went wrong" A very different viewpoint. The difference can be summarised by the end result . Police: "Investigation successful, some one prosecuted". CAA: "Investigation successful. Future crashes prevented"

[marty]

If the police treat every fatal accident as a potental homicide one could argue on that basis that they should also treat 'all' deaths as potential homicides.

Skyryder

unless a dr signs a cause of death certificate, every death is investigated for reporting to the coroner. it becomes obvious pretty quickly if there is foul play, and if there is any questions, the scene is frozen and the feds bought in. every SIDS death is initially treated as a homicide, even if it's not overtly done. the post mortem tells no lies.

an unexplained violent death scene (such as an MVA or gunshot) can easily take half a day to measure and record.

[Lou Girardin]

In my time at MOT I only attended two fatals that were suspicious. In the first there was a question as to whether the victime had been pushed out of a moving van. The cops had to mark and photograph every fragment of his skull over 50 metres of road. The second was a jumper from Grafton bridge. All the rest were quite clear cut.
Treating them all as homicides is overdoing it.

[scumdog]

In my time at MOT I only attended two fatals that were suspicious. In the first there was a question as to whether the victime had been pushed out of a moving van. The cops had to mark and photograph every fragment of his skull over 50 metres of road. The second was a jumper from Grafton bridge. All the rest were quite clear cut.
Treating them all as homicides is overdoing it.

Some DO need proper investigating Lou - i.e which car was in the wrong (not as clear-cut as it may seem at times), two occupants flung out, one dies (who was the driver?) and so on.
Some? yes, there may not be the same need to investigate.

Years ago there were probably a lot of fatals written-off that would have had a different outcome had they been looked into in depth.

We've got one down here, very mysterious was it accidental/suicide/homicide? not clear cut so requires thourough investigation.

[marty]

they are treated as unexplained violent deaths, which for all intents, could be a homicide. feds don't usually attend the scene, the SCO does that. interestingly, the sco is now often attending serious crime scenes to share their experience of measuring and recording large scenes. i attended 19 fatals in a month back in the 90's - before the advent of the SCO - i'd like to see a CAA type approach to that level of crashes.

the reality though, if you actually look at the CAA website and read the reports, the non-fatal reports are not really that in-depth, and if you have ever seen a fatal mva file, beleive me, it is a comprehensive document, as is a fatal aircraft report

check www.caa.govt.nz

[marty]

In my time at MOT I only attended two fatals that were suspicious. In the first there was a question as to whether the victime had been pushed out of a moving van. The cops had to mark and photograph every fragment of his skull over 50 metres of road. The second was a jumper from Grafton bridge. All the rest were quite clear cut.
Treating them all as homicides is overdoing it.

having 1st hand seen how incompetent the mot was at investigating and preventing crashes on sh1 huntly, i'm not surprised only 2 of them were considered suspicious. how many did you attend in total lou?

[Lou Girardin]

having 1st hand seen how incompetent the mot was at investigating and preventing crashes on sh1 huntly, i'm not surprised only 2 of them were considered suspicious. how many did you attend in total lou?

We didn't investigate fatals Marty, you should know that. We always called the cops in so they could notify next of kin.
I couldn't guess the number of fatals. Double figures, not triple.

[terbang]

James Reason considers the aviation industry as a complex productive system. He represents it by a "layers" model. The upper layer is represented by the so called "Decision Makers" (upper management, a company's corporate body, the regulatory body). A second key element is "Line Management" (those who implement the decisions made by upper management). For upper-management decisions and line management actions, resulting in effective and productive activities by the operational personnel involved, certain preconditions have to exist (for example, equipment must be available and reliable, the operational personnel have to be skilled, knowledgeable and motivated, and environmental conditions have to be safe). “productive activities result from direct action of the operational personnel, and from indirect action of the upper layers too. The final element is "Defences" or safeguards (usually in place to prevent foreseeable injury, damage or costly interruptions of service). Due to technological progress and excellent defences, accidents are seldom originated exclusively by the errors of operational personnel - frontline operators - or as a result of major equipment failures. Instead, they result from the interactions of a series of failures, or flaws, already present in the system. Many of these failures are not immediately visible, and they have delayed consequences.
Failures can be of two types, depending on the immediacy of their consequences. Active (an error or a violation which has an immediate adverse effect. Such errors are usually made by the front-line operator) and latent (a result of a decision or an action made well before an accident, the consequences of which may lie dormant for a long time. Such failures usually originate at the decision-maker, regulator or line management level, that is, with people far removed in time and space from the event).
Latent failures, which originate from questionable decisions or incorrect actions, although not harmful if they occur in isolation, can interact to create a "window of opportunity" for a pilot, air traffic controller, or vehicle driver to commit an active failure. The front-line operators are the inheritors of a system's defects. They are the ones dealing with a situation in which technical problems, adverse conditions or their own actions will reveal the latent failures present in a system. Where front-line operators have the possibility to close their window (or defences work) the result is an incident; when they do not, it is an accident. Every attempt must be made to close
those "windows of opportunity" at upper layers, in order to provide front line operators with the safest operational conditions. What is meant by that in most cases, the accident doesn't happen because operational personnel make a mistake; it happens because someone else is aware of the hazard, does nothing and remains sitting, waiting for the mistake to be made.

Here is a plug for the Rozzers. They equate to the line managers and it is their responsibility, as one of the layers, to feedback any latent failure or windows of opportunityin our roading system that they observe above or below them. We, the front line operators also have the same responsibility. In general I feel that aviation has its heart in the right place when it comes to safety and could not be accused of revenue collecting.
Here is not such a plug for Rozzers. The very public case of the Dash 8 that crashed at Palmerston North killing 4 people resulted in the police laying a manslaughter charge on the Captain, who in this rareish case survived. The end result revealed that the Bobbies at Palmerston North, with their need to throw someone in the slammer above finding our what really happened, lost. They looked a bit stupid for bringing a culture of blame into an Industry that had a far more advanced attitude towards accident investigation. Though I suspect the CAA's benign silence in this matter was in agreeance for a cheap and easy way out leaving ALPA to foot the million dollar bill.
Whilst I may blow a bit of sunshine up aviations arse, I have been working in the industry as a pilot since 1977 and have also seen the ravages of money and the oldboys network at play on our regulators. One only needs cast back to the Mt Erebus accident investigation that ended up being heavily influenced by the muldoon government of the time. As a result the real truth, even after being contested many times, was never fully revealed and the report to this day remains flawed.

[SPman]

How about the police prosecution in the Palmerston North air crash?
Blame someone, prosecute someone - it almost leaked over into Civil Aviation in NZ!
I also know of several air crashes which were NOT reported at the time - if ever.....including the Mooney into Te Arai lake many years ago.....

edit - oops - should have read the last post!

[Finn]

It would be cool if they did treat car crashes like air crashes. You'd get your car put back together for free.

[scumdog]

It would be cool if they did treat car crashes like air crashes. You'd get your car put back together for free.

Of course if you're dead it might take the edge off having your car fixed up for free......

[Finn]

Of course if you're dead it might take the edge off having your car fixed up for free......

Just as long as your tray table was up and your seat was in the upright postion, you should be fine... unless you were hit by a plane.

[Pixie]

Gooooood post. They are now deleting - everyone be aware. Today I find my slightly sarcy post questioning if the speed poll relate to over limit or excess for conditions (as after a 9mill advert campaign am not sure yet what sped means) has disappeared. So they are in defense mode. New need for subtlety damnit. So take care posting - be safeas or we won't "see ya there!:bye: "
This farcical deletion of public contributions to a forum is beginning to piss me off .
time for an email to my MP

[Pixie]

an unexplained violent death scene (such as an MVA or gunshot) can easily take half a day to measure and record.
In NZ
In Germany,however,the entire site investigation for a MVA is completed in less than 40 minutes.With minimal disruption to traffic

[marty]

is that from personal experience, or do you actually have something to back that up? is that for a fender bender or a fatal? single car/multiple car? single death/multiple death?

some substance to your claim is warranted.

[marty]

here's my reason why i am suspicious as to the 40 minute claim:

http://international.fhwa.dot.gov/Pdfs/converted_to_html/scanreports/comp/chapter2.htm#germany

[Skyryder]

All treating it as a potential homidice means is doing a thorough investigation using their gps mapping computer system and number crunching. If one of my loved ones died even if it was a one car crash i would still want to know what caused it(driver,vehicle or road factors), even if i didnt like the answer.

What would TAIC do that is different to the Serious Crash Unit?

I'm not advoating the TAIC would do anything different than the SCU. I 'm not an expert in this area. Whether the TAIC independance is considered an advantage over the SCU is the 'debatable point that I raise. I hold the view that it is. On the other side of the fence one could postulate that police could investigate air, rail, or maritime but that would be silly as the police do not have the experiance to do this. They do however prosecute. Now on this theme it could be argued the the SCU having roadside experiance through traffic enforcement, etc are the best people to investigate road crashes. But the Police are not part of the Ministry of Transport. They enforce the Ministry's policies. And it is on this basis that I believe that TAIC which is part of the MOT are better placed for this work as independants.

The traditional role of the Police is criminal investigation and prosecution. These are crimes that can be tried by a jury. This role in respect to the HP has been subverted to the enforcement Ministy of Transport policies that are not criminal and in the case of the Instant Loss of Licence are now judge jury and executioner. It is one of the fatal flaws in our society as many now view the police as the bad guys i.e. who now realy belives what they say in respect to quota's?? Just one example of mistrust.

Bit longer than intended..............but all gist for the mill.




Skyryder

[Lou Girardin]

All treating it as a potential homidice means is doing a thorough investigation using their gps mapping computer system and number crunching. If one of my loved ones died even if it was a one car crash i would still want to know what caused it(driver,vehicle or road factors), even if i didnt like the answer.

What would TAIC do that is different to the Serious Crash Unit?

Unfortunately, your curiosity shouldn't out weigh the inconvienience of closing, say, the main exit to Auckland city for 5 hours.
Other countries can carry out a scene examination in much less time. 20 mins is what's allowed on autobahns for example.

[scumdog]

Unfortunately, your curiosity shouldn't out weigh the inconvienience of closing, say, the main exit to Auckland city for 5 hours.


Just one of the 'perks' of living in Auckland no doubt?

[Lou Girardin]

No, just a bitch fight between two Police scene measurement teams.

[scumdog]

No, just a bitch fight between two Police scene measurement teams.

It would only happen in Auckland:nya:









Not enough guys here to have TWO teams.

[Squeak the Rat]

As a slight aside, how do crash teams conclude the cars speed before impact? It used to be tape measures and skid marks, but now that cars have ABS how do they guess?

If a skid mark is only 10m long before the car hit a tree how can you tell the speed from this?

And how accurate is all this?

[Lou Girardin]

Good point squeak, particularly with bikes, where the aim is to not leave skid marks.

[scumdog]

Good point squeak, particularly with bikes, where the aim is to not leave skid marks.

Especially in the Y-fronts.:yes:

[Squeak the Rat]

Interesting document attached from the National Advisor - Crash Investigations....

It explains the method for testing skid length but does not explain what is done in the case of ABS.

Of interest is page 16-18, Examples of Problems. Includes some info on motorcycles and why stats may be a bit suspect.


And quote (p18): "Enforcement is not substitute for lousy engineering" and

"It needs a society wide answer. Enforcement alone is NOT the answer to reducing the road toll"


Still - Does any one know how they measure when ABS is involved? And how many reported accidents are just the attending officers opinion about the involvement of speed?

[Ixion]

A good many years ago I had a big argument with a cop about this (can't remember whether it was a traffic cop or a policeplod -- it was back in the days of MoT , but for some reason my memory insists it was a plod - grey car).

Came steaming down a decentish curvey hill , traffic behind and in front. Car two or three in front goes round corner, oops theres a plonker on the wrong side of road. Bang. Car two in front of me locks his wheels up, screeeech-BANG. Car in front of me locks HIS wheels up --- screech . I throw out the best bower , and hear a screeeech from BEHIND me.

Oh -oh, I'm sure I can stop , but what about Percy Plonker behind me? Can HE stop? I don't fancy being a Velo sandwich.

So I steered and braked my self to the left, stopped sort of in the ditch up against a bank , a bit short of the rear of the (crashed) car in front of me, which had hit the bank sideways-headish on. And watched Percy Plonker behind me slide past, all wheels locked , and hit the car which had been in front of me. Oh, golly, glad I wasn't there.

Anyway, Plod turns up, and goes anal apeshit about measuring everybodys skid marks. With a tape measure. Insists everybody was speeding.

Comes to me

" What were you doing , how come you are not damaged, where were you?"
"Between him and him. I stopped, so I'm not crumpled".
"But the guy you *claim* (very sneering) was behind you crashed into the car in front. If you managed to stop so quickly why don't I see a motorcycle tyre marks on the road?".
"Cos I didn't lock the wheels"
"Well if you didn't lock the wheel you weren't braking as hard as you could".
"- Uh, rubbish"
Insert much argument.
"Well, say what you will, fact is I'm the only one NOT to leave a skid mark, and I'm the only one NOT crumpled" .

[Lou Girardin]

OK, I know zip about physics. But surely a light car with wide sticky tyres will stop shorter from a given speed than a heavy car on (relatively) narrow rubber.