Cavallaro v National Transport Insurance Limited - [1999] WADC 90

JURISDICTION : DISTRICT COURT OF WESTERN AUSTRALIA
IN CIVIL

LOCATION: PERTH

CITATION: CAVALLARO & ORS -v- NATIONAL TRANSPORT INSURANCE LIMITED [1999] WADC 90

CORAM: NISBET DCJ

HEARD: 10-11 AUGUST 1998 AND 28-30 SEPTEMBER 1999

DELIVERED : 25 OCTOBER 1999

FILE NO/S: CIV 1859 of 1997

BETWEEN: COSIMO DOMINIC CAVALLARO
DAVID MARK TERACE
GUISEPPE TERACE
GULIO FRANK TERACE
LEAH MAY TERACE
LINA MARGARET TERACE
REGINALD VINCENT TERACE
Plaintiffs
AND
NATIONAL TRANSPORT INSURANCE LIMITED
Defendant

Catchwords:

Insurance - Plaintiffs claim for cost of repairs to truck badly damaged in a one vehicle accident when it left the road - Defendant denies liability based on exclusion - Vehicle allegedly being used in unsafe or unroadworthy condition - Proviso - Exclusion ineffective if plaintiff proves damage not caused or contributed to by unsafe or unroadworthy condition of vehicle - Vehicle fitted with bald tyres - Application of s54(3) of Insurance Contracts Act 1984 (Commonwealth) - Discussion of principles - Result turns on own facts.

Legislation:

Insurance Contracts Act 1984 (Commonwealth)

Result:

Judgment for defendant.

Representation:

Counsel:

Plaintiffs: Mr H Kremer
Defendant: Mr A J Power

Solicitors:

Plaintiffs: H Kremer & Co
Defendant: Jackson McDonald

Case(s) referred to in judgment(s):

Bashtannyk v New India Insurance Co Ltd [1968] VR 573
March v E & M H Stramare Pty Ltd (1991) 171 CLR 506; 65 ALJR 335
Norwich Winterthur (N.Z.) Ltd v Hammond (1985) 3 ANZ Insurance Cases 60‑637
State Insurance General Manager v Harray (1974) 1 NZLR 199
Wrigley and Runciman T/as Valley Contractors v General Accident Fire and Life Insurance Corporation (1985) 3 ANZ Insurance Cases 60-627

Case(s) also cited:

Anthony Judd and Denise Judd v Suncorp Insurance and Finance (1988) 5 ANZ Insurance Cases 60-832
Forbes v The New Zealand Insurance Co Limited (1986) 4 ANZ Insurance Cases 60-731
Malcolm Gregory Stuart v Guardian Royal Exchange Assurance of New Zealand Limited (No 2) (1988) 5 ANZ Insurance Cases 60-844
Pine Hauliers Pty Ltd v SGIO (WA) (1986) 4 ANZ Insurance Cases 60-756
Sampson v Goldstar Insurance Co Limited (1980) 2 NZLR 742
SIMU Mutual Life Insurance Association v Collins (1985) 3 ANZ Insurance Cases 60-675
Steven Taylor v J Thomas & Son; VACC Insurance Co Ltd (Third Party) (1983) 2 ANZ Insurance Cases 60-524
TD Wrigley & Anor T/as Valley Contractors v General Accident Fire & Life Insurance Corp (1985) 3 ANZ Insurance Cases 60-627
Yacksley v New Zealand Insurance Co Limited (1973) 2 NZLR 231

NISBET DCJ: The plaintiffs operate a trucking business out of Donnybrook in the south west of Western Australia known as GTS Cav Transport. The majority of their business is concerned with trucking fruit and vegetables from the south west region to Perth although other cartage work is undertaken all over the State.
In about March 1996 the plaintiffs purchased a new Freightliner FL-112 prime mover, rated for 90 tonnes, which I understand to mean that that is its towing capacity. The plaintiffs had the vehicle fitted with Michelin Pilote tyres, 10 in all, the configuration being two on the front axle commonly called the steerers, then eight tyres on two axles coupled in pairs, two pairs on each axle, one on each side of the chassis. The vehicle was licensed, and was insured with the defendant.
Up to 24 February 1997 the plaintiffs, who gave evidence through Mr Cosimo Cavallaro, said that they had not experienced any difficulty with this vehicle. It was serviced every 15,000 kilometres. Mr Cavallaro also testified that Michelin Pilote tyres were specified for the vehicle new because their experience was that they would get between 140,000 and 150,000 kilometres out of a set of these tyres. As at 24 February 1997 the vehicle had done 113,000 kilometres. I understood that Mr Cavallaro was one of the principal drivers of this truck. He said that the plaintiffs had a system in place whereby the truck's tyres were inspected daily by him. Describing how the inspection was carried out he said that he normally walked around the tyres and "You hit the tyres with air pressure and once a week you just check the air pressures". And when asked about how the tread on the tyres was inspected he said "You just look at it till you get to the tyre wear".
By tyre wear he meant an indicator on the tyre that shows approximately when a tyre is down "to where its meant to be". It is clear that Mr Cavallaro was referring to the lug that is built into tyres in Australia by manufacturers which sets a piece of rubber inside the tyre groove at various intervals around the circumference of the tyre in the tread depths, which lug is 1.5mm above the bottom of the tread. This enables a tyre user to know when a tyre has reached the minimum legal limit of tread depth.[1]
[1] Regulation 802(1)(b) of the Road Traffic (Vehicle Standards) Regulations 1977 provides:
Mr Cavallaro testified that he checked the tyres on the prime mover earlier in the month of February of 1997 and decided that they were "very close to being to that limit so I turned around and ordered some new tyres". He said that the drive tyres had particularly come to his notice in this regard and by this he meant all eight of them because they were wearing out at approximately the same rate. He thought, however, that the tyres were "still reasonable to the point of still being able to use them". Having made this observation however, it is clear that Mr Cavallaro thought the tyres needed replacement within the week because he gave evidence that he had made a booking to have new tyres fitted to the truck on 26 February 1997 at a cost of some $840 - $850 per tyre.
On the afternoon of 24 February 1997 Mr Cavallaro had a job to drive to pick up a load from an orchard in Balingup, further along the South West Highway and for this purpose he used the Freightliner prime mover and fitted it up with a Kruger triaxial lead trailer which was unladen, carrying only some pallets. Before commencing the trip Mr Cavallaro said that he normally checked the engine oil, walked around and checked the tyres and just in general looked over his rig. Asked what he observed about the tyres on this day he said "that they were getting pretty low till they would slip" by which he meant all the drive tyres.
The 24 February 1997 was a day when it rained for the first time in some many weeks and the road conditions were wet. On his way out of Donnybrook heading to Balingup along the South West Highway Mr Cavallaro was obliged to stop at a railway crossing which is located at the bottom of a hill. He was behind two cars towing caravans and, approaching an overtaking lane, the caravans moved to the left and Mr Cavallaro proceeded in the overtaking lane to get past them but the tyres on the prime mover began spinning so he pulled back into line he said, meaning behind the caravans, and followed them down the highway. He had not previously experienced tyre spinning with this vehicle.
Mr Cavallaro, in travelling towards Balingup along the south west highway reached the point of the road where it crests Thomson Hill. As he crested the hill he backed his speed off to about 90 kilometres per hour and, having just crested the hill, he said his vehicle "started to skate". He observed that the particular section of road at that point was "pretty smooth". The road was "pretty wet, slippery" and it was raining at the time. He said that as the vehicle met the smooth patch in the roadway "it started to skate and it went out to the left". Asked what he meant he said:
"The arse end of the prime mover which was the drive tyres. They shot off out to the left. I took my foot off the accelerator and the jake brake came back on and then I kept on going, tried to put my foot on the brake and that didn't correct it and it came back out to the right."
Asked what came back out to the right Mr Cavallaro said "The arse end of the prime mover." Realising he was in trouble Mr Cavallaro then tried to accelerate out of his difficulties to pull the vehicles (the prime mover and trailer) back into a straight line. He again tried his foot brake and at that point the trailer deviated to the right, its rear end sliding forward at a faster rate than the prime mover causing it to effect almost a 180 degree turn to the left hand side of the vehicle coming up alongside the prime mover in a classic jack-knife position. Both prime mover and trailer then left the road ending up in a creek bed at the bottom of the hill on the left hand side of the road. The prime mover sustained considerable damage. It cost $54,500.39 to repair. It was towed from the accident scene to the plaintiff's depot at a cost of $1175.00. In the end result this is the amount of the plaintiffs' claim.
Shortly after the plaintiff had come to grief Mr Glenn Harris, driving a Western Star prime mover for Cutts Transport in Manjimup, towing a triaxle flat topped trailer, partly laden with a load of approximately 8½ tonnes, travelled this same stretch of road. The Western Star prime mover was fitted with near new tyres on its 12 wheels. As Mr Harris and his rig approached the top of the same crest previously described a vehicle flashed its lights at him indicating some problem ahead and so he took his foot from the accelerator thereby activating the Jacob's brake when he felt the prime mover begin to slip out sideways to the left. He too observed the road was wet and greasy and said that he could see the shine on the top of the bitumen. Mr Harris immediately then put his foot back on the accelerator which turns the Jacob's brake off but at the same time he pulled the hand control down on the trailer brakes and switched the Jacob's brake off on the control switch and then slowed the vehicle down whereupon he found that his rig corrected itself and, Mr Harris slowing down, observed Mr Cavallaro out alongside his truck appearing to inspect the damage.
Eventually the plaintiffs' prime mover was taken to Jandakot Truck Smash Repairs where it was inspected by a number of people including a loss adjustor acting for the defendant. The loss adjustor's attention was drawn to the tyres in consequence of which the defendant arranged for an investigation of the circumstances of the accident and, after investigation, declined liability under the policy relying upon the term:
"THIS POLICY DOES NOT COVER –
…
4.Loss, damage liability and/or compensation for damage caused while the Motor Vehicle is, or by the Motor Vehicle: –
(d)being used in an unsafe or unroadworthy condition, unless such condition could not reasonably have been detected by the Insured. Provided that this exclusion shall not apply if the Insured proves that the damage, liability or injury was not caused or contributed to by such unsafe or unroadworthy condition."
A number of witnesses were called by both plaintiffs and defendant to testify as to their examination of the tyres on the prime mover and to express their opinions as to the cause of the accident.

Evidence of observation and opinion

David Lewis was called by the plaintiff. Presently he is retired. Formerly he had been the product support manager for Dunlop and Olympic tyres having been employed by them for some 39 years. His job was to assess tyre wear and, to some degree, faults in tyres. Over the years he has inspected and reported on thousands of tyres. He inspected the tyres on this prime mover whilst they were at Jandakot Truck Smash Repairs where he measured the tread depth. His method of measurement was to take three points around the circumference of the tyre and then average the tread depths across the tyre from those three points. He testified that his measurements of the tyres were on the leading drive axle: on the left outer there was 4mm and on the left inner 4mm. The right inner was 3mm and the right outer 3mm. On the rearmost drive axle: the left outer was 1.6mm, the left inner was 0. The right inner was 0 and the right outer was 3mm. This, Mr Lewis said, meant that in plain terms there were two bald tyres being the two inner tyres on the rearmost axle. In Mr Lewis' opinion there was sufficient tread left on the drive tyres to provide appropriate traction for the vehicle. Asked why he said:
"Well, we're not talking about a passenger vehicle here, we're talking about a truck which has 10 tyres and in this particular instance there are 8 drive tyres there which in my consideration, there is more than enough to give traction to the rear of that particular vehicle and bearing in mind the so‑called bald tyres, they would still have traction or could still have traction depending on the road conditions at the time." (My emphasis.)
Mr Lewis going on to say that that was irrespective of tread depth.
Additionally Mr Lewis testified that a vehicle such as this truck, if towed in a misaligned condition would be liable to sustain a lot of abrasion to the tyres during the course of towing. There was some evidence that the chassis of this vehicle was out of alignment after the accident and the plaintiff was attempting to establish that observations as to the wear on the tyres could have been caused by it having been towed in a condition in which the whole vehicle was out of alignment. Mr Lewis however said that he doubted whether these tyres had been severely scuffed during towing.
Cross‑examined about his opinion Mr Lewis agreed that his method of averaging tread depth could be misleading and, further, not having examined properly the left outer tyre on the rearmost axle he was quite unable to say whether there were parts of that tyre which had minimum depth tread, and parts which were bare of tread. Ultimately, Mr Lewis conceded that the condition of the tyres on this vehicle must have played some part in it having left the road. Conceding that the condition of the tyres must have played some part in the vehicle leaving the road Mr Lewis said what that part was would be too hard to tell. He was asked directly in re‑examination what role the tyres played in this particular case and he answered:
"If the road was extremely greasy and wet and there was severe braking as well as cornering, one would suggest that, yes, the tyres would have played a role, but under those conditions; and there again, it would depend on how wet the road was, if there was any depth of water and as to how greasy the road was."
In February 1997 Raymond Thompson was a police officer attached to the Fremantle Crash Investigation Section. Part of his duties was to inspect tread depth on tyres of vehicles. He attended at Jandakot Truck Smash Repairs on 6 March 1997 and inspected the tyres on the prime mover. He said that he found two bald tyres being the inner tyres on the foremost drive axle. He said both of them were devoid of tread. The front right steer tyre was worn below 1.5mm on the outermost aspect of that tyre but otherwise the tread was good.
Constable Thompson explained in cross‑examination that his estimation of the state of the tyres was not made with the use of a tread depth gauge or anything like that. He used only the indicator markers on the tyres themselves. Further, he only took his measurement in one place and not at various places around the circumference of the tyre.
Frederick McKay is a brake specialist. He did not examine the tyres. The essence of his opinion was that the cause of the truck losing traction was the application of the Jacob's brake. The Jacob's brake (a.k.a. Jake brake, J brake, C brake) is a brake which, if switched on, comes on automatically on trucks fitted with this device once the foot is lifted from the accelerator pedal. It can be turned on or off by a switch located either on the steering column or on the dashboard of the truck depending on the make of vehicle and the make of the Jacob's brake. It has much the same effect as changing from a high gear to a low gear under speed would have ie, the compression of the engine acts as a braking force through the gearbox to the drive shaft to the axles to the wheels.
Mr McKay explained that the Jacob's brake is not a variable brake. Once applied the amount of resistance it creates on the turning point of the rear wheels of the prime mover is constant whilst on the trailer there was no brake application at all. Accordingly, he said, the tendency was that once the prime mover's rear wheels started to lose lateral stability, the trailer with its full weight continued to push and continued to jack-knife that vehicle out of alignment. He thought the reaction of Mr Harris to the situation that he was confronted with compared with that of Mr Cavallaro was the correct method to overcome a tendency to jack-knife. He said one of the obvious difference between the two drivers was that Mr Harris realised the situation he was in and released his Jacob's brake which stopped the truck from giving resistance whereafter he applied the trailer hand control which pulled the trailer brakes on and had the tendency to hold back against the truck and at the same time he continued to accelerate the prime mover to pull it out of the jack-knife situation. Compare this he said to Mr Cavallaro's situation where the vehicle commenced to jack-knife which would have put the vehicle out of its lateral alignment and whilst he released his Jacob's brake he then applied his foot brake which in turn caused all the wheels to lock in a position where it was already out of alignment and going through an s-bend it would continue to slide and jack-knife.
Mr McKay further thought that once the vehicle went into a slide the condition of the tyres had no bearing on the matter. Mr McKay was obviously very heavily influenced in his assessment of the situation by what happened to Mr Harris. In fact its fair to say his opinion is almost entirely dependent upon Mr Harris' experience for he said:
"There's a point here that I think I've got to emphasise, that is based on the effect of the second truck that brings me to my conclusion of what happened on the first truck, because if it was tyres solely then it would never have happened to the second vehicle."
Even assuming Mr Cavallaro's truck had good tyres and assuming Mr Cavallaro conducted himself in the same manner then he would still end up in the same situation.
As is evident from some of the passages from Mr McKay's evidence that I've mentioned above, he begins his analysis with Mr Cavallaro's prime mover losing traction just over the crest of the hill. What he never addresses himself to is the cause of the vehicle losing traction. He assumes it is wholly and solely to do with the road conditions at the time, again, because of Mr Harris' experience. When pressed specifically in cross‑examination to say whether the tyres could have contributed to this loss of traction he was obliged to admit that he didn't know and, acknowledging that the state of the tyres may have been a contributing factor said that he still believed "… there was more than just loss of tyre traction that contributed to it" which, of course, begs the question.
Brian Johns was the manager of Jandakot Truck Smash Repairs in March 1997. He recalls the prime mover being brought into the repair shop by a tow truck. It had been what they call in the trade "front lifted" by which I understand that the front wheels were lifted off the ground and the vehicle was towed with at least four of its eight drive tyres in contact with the road at all times. Mr Johns inspected the vehicle and noted the damage and thought that the chassis might have been twisted,so he measured it and confirmed that it had indeed been twisted. Apart from noticing that the tyres were low on tread he didn't inspect them.
Mr William Apgar was the final witness called by the plaintiffs. He is a chartered professional engineer. He holds appropriate qualifications and offered the court his opinion as to the cause of the accident. He produced a comprehensive report which was received in evidence as Exhibit P14. Mr Apgar inspected all 10 tyres on two occasions and carefully measured their tread depth with an electronic digital caliper accurate to within 0.01mm. He then proceeded to mark out the tyres with chalk delineating those parts of the tyres which had a tread depth of less than 1.5mm and he then photographed the tyres with the chalk marks. He then went to the trouble of calculating the percentage of legal tread on each of the four tyres which were noted to have a tread depth of less than 1.5mm. I did not quite understand the significance of this analysis either during Mr Apgar's evidence or since giving it further consideration. It seems to me that the legality of tread depth can only be a reference to the Road Traffic Vehicle Standards Regulations 1977, previously noted. This requires that every tyre fitted to every vehicle to be used on a road must have a tread depth of not less than 1.5mm on every surface that is to come in contact with the road. If any part of any tyre does not comply then it is illegal. There are no degrees of illegality,apart from which the terms "unsafe" and "unroadworthy" used in the exclusion clause in the defendant's policy are not to be equated with a failure to comply with the Road Traffic Vehicle Standards Regulations 1977. The two may at times meet or even overlap, but they are not the same.

Returning to Mr Apgar's evidence he then proceeded to calculate the percentage of legal tread area on all 10 tyres coming up with the answer of 84 per cent. Again I didn't then and still don't understand the purpose of this. Mr Apgar did concede that it was an artificial exercise and explained that he didn't use this calculation in coming to his opinion which made me wonder why it was there in the first place.
Next, Mr Apgar expressed the opinion that inadequate attention had been paid to the fact that the tyres may have been excessively worn following the accident by reason of having been towed while the wheels were misaligned because of the damage to the truck's chassis. Mr Apgar, having examined the tyres concluded that as they lacked circumferential scrape marks on both inner rear drive tyres this supported his contention that those tyres had been severely worn in the towing operation. Shown a set of 14 photographs taken by the defendant's tyre expert Mr McKinlay, Mr Apgar was obliged to concede in cross‑examination that he was wrong.
Next, Mr Apgar expressed an opinion in respect of the coefficient friction of the drive tyres, something that he said could be expressed as an average, something I again had difficulty understanding both whilst Mr Apgar was giving evidence and subsequently. A coefficient is simply a multiplier that is used to measure some property of a particular substance for which it is constant while differing for different substances. How can you have an average constant? The coefficient of friction of each tyre will be what it is for each part of the tyre in contact with the road surface at any one time. Assuming that the coefficient of friction of each part of each tyre at any given time is a measure (or rather, more accurately, an attempt to measure) the grip of that part of the tyre to the road surface then how can you have an average grip? Either the tyre will grip or it won't and no averaging of the part of the tyre that will grip with that part where it won't, will make up for or compensate for the physical fact that there is no grip in that part of the tyre.
As with averaging the legal tread depth, the idea of averaging the co‑efficient of friction is meaningless where, at a speed of 90 kilometres an hour, a tyre with a circumference of 3½ metres or so will perform five complete revolutions every second, meaning that if a tyre has 60 per cent of its surface devoid of tread then 60 per cent of that tyre surface will be in contact with the road five times a second. The probabilities are that at any given time the bald surface of a tyre partly bald and partly with tread, will be in contact with the road surface. Where a tyre is wholly bald of course that tyre and all other bald tyres will have no tread in contact with the road surface at any time.
When Mr Apgar reached the conclusion of his opinion, therefore, I was not minded to attach too much weight to it because of what I see as being fundamental flaws in it. Nevertheless, he too expressed the opinion that after an examination of the effect of the activation of the Jacob's brake upon this truck it was the Jacob's brake which was solely to cause for the accident. He said the effect of the Jacob's brake being activated on the drive wheels of the truck on a slippery patch of road in wet conditions caused the drive wheels to lock up as it were whilst the trailer and its mass continued to apply force to the rear of the prime mover thereby combining to push the prime mover out of alignment. This was the beginning of the jack‑knifing from which Mr Cavallaro could not extract himself. In this regard however Mr Apgar was also obliged to concede in evidence (more than once) that he could never know whether the drive tyres contributed to the accident.
There are some other difficulties too with Mr Apgar's evidence. These, as with his admission that he was wrong in his conclusions in respect of post‑accident tyre wear, demonstrate that whilst he has undoubted expertise in other areas, the performance of tyres on trucks is not a speciality for him. In this I refer to his failure to observe that the left rear outer tyre had been incorrectly fitted on its rim which was the cause of the uneven wear noted by Mr Apgar as indicating that this tyre was "seriously out of round". Then again too, there was the unfortunate evidence which indicated that Mr Apgar may have pre‑judged the situation. Mr Peter Wall is an articled law clerk in the employ of the defendant's solicitors, who facilitated Mr Apgar's inspection of the tyres which were kept in self‑storage facilities in Harborne Street in Wembley. He testified and I accept that Mr Apgar said to him when they first met, before he had actually inspected the tyres, words to the effect: "I cannot believe that the insurance company is denying this man indemnity on his policy on the basis that two tyres out of ten were not roadworthy." Then, Mr Wall testified that during the course of Mr Apgar's inspection he said words to the effect: "every single trial that I have given expert evidence on, they have won."
This was put to Apgar in cross‑examination. He admitted that he said that most of the trials that he had given evidence on had come out favourably for the client and he admitted also that he said that he could not believe the insurance company was not paying because there were two tyres out of ten that might be considered not roadworthy. These indicated to me that Mr Apgar may not have approached his investigation with a clear mind, an observation exacerbated by his explanation in re‑examination that he was not feeling particularly well that day. Mr Wall however, noticed no difficulties with Mr Apgar's health. He observed Mr Apgar to have been very coherent at the time of discussions with him.
Mr Lester Rowe is a former policeman who spent some time in the Police Traffic Accident Branch Plan Room preparing plans of crime and accident scenes. He also spent four years in the Accident Inquiry Section of the Police Traffic Branch. He worked with the insurance loss adjusters engaged by the defendant insurer and was asked to prepare a plan of the scene of the accident, which he did. He obtained the Main Roads Department original drawings, visited the scene of the accident and took photographs which he collated with the drawings. This was admitted into evidence as Exhibit D2.
Paul Malone is a motor vehicle assessor whose duties include assessing damage to vehicles involved in accidents. He is a qualified mechanic by trade and a licensed vehicle examiner for the Road and Traffic Authority in New South Wales. He was asked to assess the plaintiff's claim for damage to the prime mover and attended at Jandakot Truck Smash Repairs in order to examine the truck. The state of the tyres was drawn to his attention so he measured them and took some more photographs of them which were admitted into evidence. He measured the depth of tyre tread with a tyre measuring gauge telling the court that he only measured the worst aspect of the tyre surface. He measured the four tyres on the rear most drive axle as having tread depth respectively of nil, nil, nil and 2.5mm.
Peter Frampton is a principal in the firm of insurance investigators and assessors known as Frampton Warner & Associates. He spent some years in the South Australian Police Service where he was trained as an accident investigator. On leaving the South Australian Police Service in 1984 he took up employment as an insurance investigator and has been in that line of business since that time. He was instructed by the defendant insurer to investigate the accident. He took a statement from Mr Cavallaro which was admitted into evidence as Exhibit P9. He testified that when he first spoke to Mr Cavallaro about the accident the details he was given were different from those which ultimately appeared in that exhibit. He too took some photographs of the truck tyres and measured the tread depths on them at the premises of Jandakot Truck Smash Repairs. He took tread depth measurements across each tread of each tyre and relevantly measured the tyres on the rear drive axle. On the left inside tyre his measurements were 0, 0, 0 and 0mm from outside to the inside of the tyre. On the left outside tyre 3, 0, 0 and 3mm again from the outside to the inside of the tyre. On the right side of the rear drive axle he measured the tread depth on the outside tyre from inside to out at 3, 0, 0 and 4mm and on the right inside tyre from inside to out 0, 0, 0 and 0mm. In taking these measurements he used a standard tread depth gauge. He never averaged his measurements. They were taken in only one location on each tyre.
The defendant's tyre expert was Mr Robert Mackinlay. He has considerable experience in assessing the performance of tyres and had worked in the tyre industry for approximately 20 years. He is contracted to Goodyear as a field engineer which involves assessing the performance of large earthmover tyres and reporting to the factory on their performance. A lot of this work is done overseas. He has also worked for South Pacific Tyres (a combination of Goodyear and Dunlop) as a product analyst based in Western Australia. This involved inspecting tyres which had failed and reporting to the factory his opinion of the reason for the failures. That role also included the investigation of vehicles involved in accidents which were alleged to have been caused by either the tyre being faulty or worn out. This was a task upon which he was engaged for some 14 years whilst employed with South Pacific Tyres. He was engaged by the defendant to examine these tyres which he did after their removal from the prime mover and when they were in storage. He examined them in December 1997. Mr Mackinlay subjected the tyres to a close inspection measuring the tread depth, closely visually examining them and photographing them. He took six readings going across the width of the tread of each tyre and he chose as his readings the lowest set of readings, by which he explained in cross‑examination that he looked for the areas that were worn most on the tyres and then he took a selection of readings from around the tyre. He explained that whilst he found lower readings in some parts of the tyres he was looking for the lowest set of readings across the width of the tread. These gave rise to his measurements. As with a number of other observers he did observe that the front right steer tyre had less than 1.5mm tread on the right edge circumference of the tyre but as most experts agreed that this was irrelevant to their investigations in this case I shall give his readings for the rear drive tyres which, proceeding from the left outmost through to the right outmost, were as follows: left outmost: 0.0, 0.0, 0.0 and 2.6 and, at 180 degrees around from these readings those readings were for the same tyre 3.8, 2.5, 2.2 and 2.6mm (indicating a seriously deformed tyre or as Mr Apgar put it, a tyre seriously out of round). For the left inner tyre the measurements were 1.0, 0.0, 0.0 and 1.0mm. For the right inner: 1.3, 0.4, 0.4, 1.0mm. The right outer tyre had all depths at 1.5mm or above, as did all other tyres on the truck.
His close examination of the tyres enabled him to say that there had been no excessive wear caused to the tyres on the rear drive axle by it having been towed from the accident scene to Jandakot in a misaligned condition. This was because the circumferential score marks he observed on the tyre (and which Mr Apgar had failed to observe) which had been caused during the accident or immediately afterwards, along with the transverse scoring marks on the tyres, would have been removed had the tyre undergone any further heavy abrasion by recovery procedures or towing. Further he said that a tyre consistently towed or used in a misaligned position would have a noticeable pattern of wear that was not observable on these tyres or any of them.
In Mr Mackinlay's opinion whilst the application of the Jacob's brake was the cause of the initial loss of adhesion or traction it was his opinion that the tyres maintained their loss of adhesion due to their condition. Put another way, whilst the application of the Jacob's brake may have started the skid, had the tyres been good they would have arrested it. As he said on a number of occasions during his cross‑examination, it was his opinion that the main two contributing features of this accident was the application of the Jacob's brake and the poor condition of the tyres. Mr Harris' experience was explained in Mr Mackinlay's opinion by a number of factors: firstly it could not be said with any precision how Mr Harris' truck was located on the road, secondly the effect of the laden trailer with its trailer brakes being applied with good tyres being more effectively able to pull up the jack‑knifing, thirdly driver reaction and fourthly Mr Harris' rig was fitted with all new tyres.
Mr Bohdan Generowicz is an accident analyst. He holds the degree of Bachelor of Science in Engineering from London University and a Master of Science in Highway and Traffic Engineering from Birmingham University. He is a member of the Institute of Civil Engineers of the United Kingdom and a similar organisation in Australia. He too examined the circumstances surrounding this accident and the tyres on the prime mover. In his opinion there was no doubt in his mind that the chief culprit was the first rain of the season. He explained why, although it is a phenomenon known to all of us. In this situation he said the steepness of the road, its smooth surface in combination with the first rain of the season "created a lethal ingredient which the skidding or loss of grip was almost inevitable".
Asked what role the three tyres deficient in tread on the rearmost axle of the prime mover had to do with the accident he said:
"The purpose of the tread is to dislodge the surface water so that the tyre composition can, as much as possible, roll on the actual surface of the road. The absence of the tread simply means the tyre was not able to displace the greasy water which means, in effect, that if a treaded tyre would ride on a wet surface, then a treadless tyre, in effect, was riding on a very thin film of greasy water."
This he said caused the risk of the tyre losing its grip to rise "dramatically". He said that the risk of a bald tyre losing its grip was many times higher than with a treaded tyre. In cross‑examination he confirmed that road, weather and tyres were the cause of this accident.
Finally, this seemingly endless evidence of experts was completed with the evidence of Mr Martin Simms. Mr Simms hold the degree of Bachelor of Applied Science in Mechanical Engineering from Curtin University. He is a fellow of the Institute of Engineers of Australia and a professional engineer. Before he graduated he was a machinery inspector for four years with the Department of Labour and Industry (now known as Worksafe WA). He worked with the Public Works Department for a year in its plant investigation section and for 12 years he was the engineer in charge of the technical service division of the Road Traffic Authority and then the Police Department in which capacity he was responsible for the management of the vehicle inspection system utilised throughout Western Australia. Additionally, he has been the representative of the Minister for Transport (WA) on the Motor Vehicle Certification Board, the Vehicle Standards Advisory Committee and the Advisory Committee on Unsafe Products in Transport. He has investigated mechanical failures in accidents and vehicle testing for compliance with Australian Design Rules for vehicle performance.
In Mr Simms' opinion once jack-knifing has started unless it can be arrested in its very early stages it will become irreversible. And, cross‑examined upon a comparison of Mr Cavallaro's experience with that of Mr Harris, he said that he could only conjecture as to the parameters which work to reduce the likelihood of a jack-knife which worked in Mr Harris' favour and he thought those parameters would include the condition of his tyres. He explained that whilst he would stop well short of saying that the fact that he had good tyres was "the saving grace" this was because he didn't know and didn't have enough information to be able to express that opinion definitively. In his opinion he could not say whether the Jacob's brake was the main contributing factor to this accident or the tyres but he stressed that it was beyond dispute that a tyre which for all practical purposes is bald, having no tread pattern whatever, will have significantly less capability of gripping a wet road or indeed a slippery road than tyre with some remaining tread.
Mr Simms' opinion is best expressed by the conclusion to his report received into evidence as Exhibit D13. It is as follows:
"The literature concerning research into tyre performance is extensive and it is universally accepted by tyre safety researchers that the absence of tread depth is a significant factor in reducing traction in tyres subject to wet road conditions. It is also within the experience of the ordinary motorist that this is true and the plaintiff also apparently experienced slippage whilst ascending hills prior to the accident site.
It is not possible to say that this accident would not have happened with good tyres fitted. The speed at which a combination with good tyres will jack-knife will be higher than the speed at which a combination with bald tyres will jack‑knife, all other factors being equal. The presence of bald tyres is likely to have been a factor in this accident.
Road Safety research has confirmed beyond any doubt that bald tyres generate lower braking and cornering forces than tyres with adequate tread when operated on wet roads. As such, a vehicle with bald tyres will lose traction sooner than one with good tyres under equivalent wet road conditions. Any argument to the contrary ignores a large body of research and practical experience. It is not possible to prove that the bald tyres did not cause or contribute to this accident. On the balance of probabilities it is more likely that the bald tyres contributed to the accident than that they did not."

Findings

I am persuaded that three of the five drive tyres on the prime mover were bald, they being the left outer, the left inner and the right inner tyres on the rearmost drive axle. I do not accept Mr Cavallaro's evidence that these tyres were not in the condition they were in as observed by all of the expert and non‑expert observers before he commenced his journey to Balingup. The tyres were defective to his certain knowledge, he having booked the vehicle in for tyre replacement prior to the journey, the tyres to be replaced two days afterwards. Further, I reject the plaintiffs' contention that there was no reasonable opportunity for inspection of the defective tyres. Clearly they had been inspected and found wanting otherwise there would not have been any arrangements made for new tyres to be fitted and, finally, lest there be any doubt about it I reject the plaintiff's contention that damage to the tyres was caused by it being towed in a misaligned condition. I accept the evidence of the defendant's expert Mr Mackinlay on this issue and, in the event there is any vestige of Mr Apgar's assertion to the contrary after he admitted that he was wrong, then I reject his opinion on the matter.
This brings me to the cause of the accident. As the balance of the expert and other testimony reveals, there was more than one cause of this accident. In my opinion the causes were the road conditions at the time, driver error, the effect of the application of the Jacob's brake and the condition of the tyres.
Without doubt the particular surface of the road at the point where the prime mover first lost traction was smooth and shiny. The first rains after several weeks would tend to make the road surface slippery, the rain releasing an accumulation of worn rubber and oil to the surface and whilst the road was obviously comparatively well drained it was nevertheless wet and slippery. When the plaintiff came upon this scene and felt his drive tyres lose traction he was travelling at too high a speed for the road conditions at the time. This should have been abundantly clear to him from the fact that he had spun his tyres while attempting to overtake the caravans a short time before and, being quite unable to obtain sufficient traction out of his tyres he was compelled to drop back and fall into line behind them. This should've been a strong indication to him that he was driving too fast for the road conditions with the tyres that he had which he had known were low on tread at least but, as I find, were as to three of them, bald. This observation accords with the comments made by the plaintiffs' own counsel from time to time throughout the proceedings that Mr Cavallaro was probably travelling too fast for the road conditions. The problem did not stop there however. Mr Cavallaro should have appreciated that the effect of the Jacob's brake and the footbrake were such as to cause the prime mover to slow down at a rate faster than the trailer it was towing and with the effect of the trailer pushing upon the rear of the prime mover in a situation where it was on a slippery road and losing traction, this was simply the wrong evasive action to take at the time. Had Mr Cavallaro used the measures used by Mr Harris and, as I find, had his vehicle been fitted with new tyres as had Mr Harris' vehicle, then this accident probably would not have occurred. Further, I find that there is a strong likelihood that Mr Cavallaro's actions, unsatisfactory as they were, would have enabled the truck to regain traction if its tyres had not been bald.

The exclusion clause

Counsel for the defendant submitted during the course of the hearing that if I was to find that the condition of the tyres rendered the vehicle unsafe or unroadworthy then the plaintiff could not take advantage of the proviso in the clause even if I found that the unsafe or unroadworthy condition of the tyres only contributed to the cause of the accident to the extent of one per cent. In my opinion this cannot be right. It would lead to some absurd and inequitable results. In my opinion the proviso when it speaks of the damage being "not caused or contributed to by such unsafe or unroadworthy condition" must be interpreted such that a miniscule or even minor degree of contribution will not avoid the cover provided by the policy.
As we all know issues of causation and what constitutes a contributory cause or not have bedevilled the law for years. It has interested psychologists too: see for example Ogden and Richards' "The Meaning of Meaning" (Routledge & Kegan Paul Ltd 10th ed 1966 ). Regrettably however, lawyers are unable to deal with causation in the way psychologists do, but there is nevertheless for lawyers some truth in what they wrote (p55):
"A Cause indeed, in the sense of a something which forces another something called an effect to occur, is so obvious a phantom that it has been rejected even by metaphysicians."
The High Court pondered the difficulty in March v E & M H Stramare Pty Ltd (1991) 171 CLR 506; 65 ALJR 335 in the context of an action for damages in tort. There the High Court rejected the notion of the "but for" test of causation in negligence cases. It seems to me that there is little difference, if any, with the correct approach to construing the notion of cause in an insurance policy and the notion of cause in the sense of being causative of damage in negligence. If there is a difference it could only be a semantic difference. And there is nothing about the notion of causation itself which precludes multiple causes, a situation recognised for negligence cases by the contributory negligence legislation abrogating the last opportunity rule.
Reference to authority is not particularly helpful in the instant case either. Cases decided before the Insurance Contracts Act 1984 (Commonwealth) and particularly the New Zealand cases suggest that there is no need for a causal connection to be established between the condition of an allegedly defective motor vehicle and the incident out of which the claim arises: State Insurance General Manager v Harray (1974) 1 NZLR 199 and Wrigley and Runciman T/as Valley Contractors v General Accident Fire and Life Insurance Corporation (1985) 3 ANZ Insurance Cases 60-627. But those cases were dealing with an exemption clause which denied liability for any "damage … sustained or incurred whilst any vehicle in respect of which indemnity is provided … is … (d) being driven in an unsafe condition". So those authorities are not particularly helpful (my later remarks about them also refer).
It seems to me that the appropriate test of whether or not a cause is a contributing cause to an event within the meaning of the exclusion clause in this policy involves a two step process, the first of which is to determine that there was on the balance of the evidence a real as opposed to a merely theoretical possibility that the contributing cause contended for did in fact contribute in some way to the event. Then, having determined that, the second is to find whether the cause was significant or insignificant. If it is found that a condition of the vehicle was a real contributing cause to the event but that its contribution was insignificant, then in my opinion the proviso does not apply to enable an insurer to avoid liability under a policy worded such as this.
Hence, it seems to me that the proper way to dispose of this matter is, accepting that the onus of proving that the prime mover was being used in an unsafe or unroadworthy condition was on the defendant (Bashtannyk v New India Insurance Co Ltd [1968] VR 573) then in my opinion the defendant has discharged that onus in this case. This is because having three bald tyres out of eight drive tyres in this vehicle and driving it in the conditions pertaining at the time constitutes use in an unsafe or unroadworthy condition.
It is true as was found by the Court of Appeal in New Zealand in State Insurance General Manager v Harray (supra) that bald tyres of themselves will not render a vehicle unsafe or unroadworthy, which terms have to be considered at the time of the event giving rise to the claim. In that case a vehicle had bald tyres but the road conditions were dry and it was common ground that the state of the tyres could not be proved to have contributed to the accident. And whilst it was also accepted as previously noted that there was no obligation on the insurer to prove any causal connection between the bald tyres and the accident (even where the exclusion clause there under contemplation was: "(d) being driven in an unsafe condition and for the purposes of this exception the term 'unsafe condition' shall include such condition as may result in damage to the vehicle or any part or component thereof") the court was careful to show that there may have been circumstances in which the bald tyres were unsafe and unsatisfactory and specifically included in that if the road was wet (by citing with approval the decision of Winneke CJ in Bashtannyk's case (supra).
Next, as I have already found as a fact, the unsafe or unroadworthy condition of this vehicle could reasonably have been detected by the plaintiffs, the onus of negating which was on them (Pine Hauliers Pty Ltd v SGIO (WA) (1986) 4 ANZ Insurance Cases 60-756) and, the onus being on the plaintiffs to prove that their damage was not caused or contributed to by the unsafe or unroadworthy condition of the vehicle, they have failed to discharge that onus.

Insurance Contracts Act 1984 (Commonwealth)

Section 54(3) of the Insurance Contracts Act (1984) (Commonwealth) provides:
"Where the insured proves that no part of the loss that gave rise to the claim was caused by the act, the insurer may not refuse to pay the claim by reason only of the act."
"The act" there referred to is an act of the insured which would otherwise entitle the insurer to refuse to pay a claim: S54(1). In this case that act is the act of driving the vehicle in an unsafe or unroadworthy condition.
The plaintiffs, relying on a passage in Insurance Law in Australia Sutton 2nd ed (Law Book 1991) at para 10.13 submitted that s54(3) did not require the plaintiffs to prove strictly that "no part of the loss that gave rise to the claim was caused by the act" but rather that the unsafe or unroadworthy condition of the vehicle was not the proximate or dominant cause thereof. The passage in Sutton should be set out in full because, in my opinion, it is not correct.
"10.13 A exception clause (sic) which is in common use in comprehensive motor vehicle insurance policies is the provision which exempts the insurer from liability for any loss or damage sustained whilst the vehicle is being used or driven in an unsafe condition. This may be qualified by adding first an exception to the exception clause to meet the situation where the unsafe or unroadworthy condition could not reasonably have been detected by the assured, and secondly a proviso that the exception clause will not apply if the assured proves that the loss or damage was not caused or contributed to by such condition. These qualifications would appear to reflect the current position as established by s54 of the Insurance Contracts Act 1984 (Commonwealth) subject to one point of difference exemplified by the use of the word 'contributed' in the proviso above. Under s54 the insurer must show that the vehicle was unsafe or unroadworthy and that the defect was capable of causing or contributing to an accident, while the assured must prove either that the defect was in fact not the cause of the mishap or, if it was, it was not reasonably possible in the circumstances for the assured to detect and remedy it. Where another person was partly to blame for the accident, the assured may be able to recover part of the loss from his insurer. But the assured is not required to prove that the defect did not contribute to the accident, only that it was not the proximate or dominant cause thereof, and on this aspect s54(3) differs from the proviso set out above. Thus if a motor car, whose tyres are worn smooth making it unroadworthy, is driven at excessive speed on a wet road and as a result spins off the road on hitting surface flooding, the dominant cause of the accident is no doubt the excessive speed, but the smooth tyres may well be a contributing cause. It seems that the assured may be able to take advantage of s54(3) and obtain payment of the claim on proof that the effective cause of the loss was the excessive speed of the car." (Citing Norwich Winterthur (N.Z.) Ltd v Hammond (1985) 3 ANZ Insurance Cases 60-637.)
I have read and re-read the authority said by the author to support this proposition and can find no support for the proposition in it. That case was decided on appeal by the Court of Appeal of New Zealand accepting the findings of the judge below as to his preference between experts, the one for the plaintiff testifying that the worn tyres did not cause the damage, and the other for the defendant insurer saying that they did. The Court of Appeal made it plain, after a careful examination of the evidence, that it accepted that the findings of the trial Judge accepting the evidence of the plaintiff's expert and rejecting those of the defendant's expert were open on the evidence. Those findings were to the effect that if the bald tyres did contribute to the accident that contribution was minimal and it was fully expended by the time the car came into collision with a tree causing the damage in question.
In my opinion s54(3) of the Insurance Contracts Act 1984 (Commonwealth) affords no relief to the plaintiffs. They are required by that section to prove that no part of their loss was caused by the unsafe and unroadworthy condition of the vehicle by reason of its three bald tyres. As my findings already demonstrate, this they have not done. Further, the preponderance of acceptable expert evidence suggest that it would, in the circumstances of this case, at the very least, even if I'm wrong on causation, be impossible for the plaintiffs to prove that no part of their loss was caused by driving the vehicle with its three bald tyres.
Accordingly it follows that the plaintiffs' claim must be dismissed and I so order. I will hear the parties as to costs.

"Every tyre fitted to a motor vehicle shall unless specifically exempted by the Director General have a tread pattern of a depth not less than 1.5mm on all parts of its surface which normally come into contact with the road surface."