JURISDICTION	:	SUPREME COURT OF WESTERN AUSTRALIA 

TITLE OF COURT	:	THE COURT OF APPEAL (WA) 

CITATION	:	SHIRE OF CORRIGIN -v- HUNTER HOLDINGS PTY LTD [2007] WASCA 31 

CORAM	:	STEYTLER P
PULLIN JA
BUSS JA 

HEARD	:	19 DECEMBER 2006 

DELIVERED	:	8 FEBRUARY 2007 

FILE NO/S	:	CACV 149 of 2005 

BETWEEN	:	SHIRE OF CORRIGIN
Appellant
 
AND
 
HUNTER HOLDINGS PTY LTD
Respondent 

ON APPEAL FROM: 

Jurisdiction	:	DISTRICT COURT OF WESTERN AUSTRALIA 
Coram	:	CRISFORD DCJ 
Citation	:	HUNTER HOLDINGS PTY LTD -v- SHIRE OF CORRIGIN [2005] WADC 211 
File No	:	CIV 504 of 2001 

Catchwords:
Tort - Negligence - Road traffic authority - Truck driver injured in single vehicle accident at bend in road - Speed and deficient geometry in the road construction contributed to the accident - No warning signs erected before the corner - Contributory negligence of truck driver 
Legislation:
Nil 
Result:
Appeal dismissed
Cross­appeal allowed in part 
Category:    B 

Representation:
Counsel:
Appellant	:	Mr P G McGowan
Respondent	:	Mr T Lampropoulos 
Solicitors:
Appellant	:	Phillips Fox
Respondent	:	Srdarov Richards Burton 

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

Bennett v Minister for Community Welfare (1992) 176 CLR 408
British Fame (Owners) v MacGregor (Owners) [1943] AC 197
Chappel v Hart (1998) 195 CLR 232
March v E & M H Stramare Pty Ltd (1991) 171 CLR 506
Medlin v State Government Insurance Commission (1995) 182 CLR 1
M'Kew v Holland & Hannen & Cubitts (Scotland) Ltd [1970] SC (HL) 20
Pennington v Norris (1956) 96 CLR 10
Podrebersek v Australian Iron & Steel Pty Ltd (1985) 59 ALJR 492
Rosenberg v Percival (2001) 205 CLR 434
Wynbergen v Hoyts Corporation Pty Ltd (1997) 72 ALJR 65

1	STEYTLER P:  I agree with Pullin JA.
2	PULLIN JA:  This is an appeal against the judgment of Crisford DCJ, who ordered the appellant to pay the respondent damages for property damage arising out of a motor vehicle accident.
3		The accident happened at about 3 pm on 3 March 2000.  Anthony John Ferguson ("Ferguson"), an employee of the respondent, was driving a Scania cab which was towing a tanker filled with ammonium nitrate emulsion.  During the trip Ferguson was diverted onto a secondary road near the town of Corrigin.  While travelling on the detour road he negotiated a bend in the road at an unsafe speed and rolled the vehicle.  He was unhurt but the vehicle was damaged.
4		The facts and evidence set out below are taken from the trial Judge's reasons:
Facts and evidence
5		Ferguson, who was aged 30 years at the time of the accident, was an experienced truck driver.  After he left school he joined the Army.  Whilst in the Army in 1990 he did a six week truck driving course and achieved his rigid truck licence.  The following year he acted as instructor in a driving course.  
6		He had driven semi‑trailers and road trains since 1993.  
7		At the relevant time he held a Western Australia B and C class licence which covered the driving of road trains.  He also held a dangerous goods licence which covered the carting of ammonium nitrate emulsion, a dangerous chemical.  He had no traffic convictions associated with the driving of trucks or heavy vehicles.  
8		On Friday 3 March 2000 he was to transport a load of ammonium nitrate emulsion from Kalgoorlie to Collie, a job he had performed numerous times before for Hunter Holdings.  
9		The total gross weight of the vehicle was around 44 tonnes.  The Scania cab was 8 feet wide and the whole vehicle was about 38 to 40 feet long.  Seated in the cab a driver was some 12 feet off the ground.  Ferguson commenced work at 6.30 am.  He loaded the vehicle and left Kalgoorlie at about 7.54 am.  Shortly after leaving, the truck developed an overheating problem and a replacement truck was provided.  The journey was resumed mid-morning.  He had lost about an hour.  He denied he was in a hurry or was working to a fixed schedule.  

10		Mid-afternoon he encountered a road block somewhere between Bruce Rock and Corrigin due to flood waters.  He detoured, as indicated by signs, to the right and followed Hancock Road, a secondary road.  
11		This was a single lane bitumen road roughly 10 feet wide with dirt shoulders.  It was in good condition for a single lane road.  The vehicle was fitted with a speed limiter.  It was not able to travel at a speed greater than 100 kmh.  That is, it was not able to exceed the speed limit for trucks.  Despite this, it was company policy to travel no faster than 90 kmh.  This policy was based mainly on fuel economy.  
12		Ferguson's evidence was that after following Hancock Road for 10 kilometres on a straight flat stretch he approached a rise in the road.  Before he reached the crest he observed some grain receival sheds to his right through the trees.  He suspected the road would go in the direction of the sheds.  
13		Ferguson gave evidence that the rise to the crest was gradual.  He remained on the bitumen of the single lane road and when he came over the crest he observed no vehicles coming towards him in the opposite direction.  Prior to reaching the crest he gave evidence under cross-examination that "to a certain extent" he could see the road ahead.  
14		From the top of the crest he gave evidence he noticed a "slight deviation in the road at the bottom" of the rise.  He took his foot off the accelerator.  Given the decline he simply maintained his speed.  In a statement made in hospital on the evening of the accident he stated he came over the crest and saw there was a "reasonably dramatic bend to the right".  The statement says as soon as he saw the corner he "hit the brake to slow down" as quickly as he could.  
15		In his evidence, he said when he was halfway down the slope he realised the bend was tighter than anticipated.  He braked at this point.  He put the left hand wheels on to the dirt to enable him to take a wider sweep through the corner.  He braked as hard as he could before he got into the corner and commenced to turn.  His next recollection was standing on the side of the road with the vehicle on its side in the trees.  He had been knocked out.
16		The speed limit on the road was 110 kmh but limited to 100 kmh for heavy vehicles.  Ferguson gave evidence at trial he was travelling at approximately 90 kmh when he arrived at the crest of the hill.  Five days after the accident he gave a statement he was doing approximately 90 ‑ 100 kmh.  The evening of the accident, in hospital he described his speed as about 100 kmh.  
17		Relatively uninjured, he was hospitalised overnight and returned to his employment two weeks later.  He then travelled the same route.  A 70 kmh advisory speed sign had been freshly installed.  This was combined with a sign indicating the shape of the road ahead.  He attempted to take the same corner at 60 kmh but he still felt the truck rolling.  
18		Ferguson gave evidence that, from his experience as a truck driver, he could reduce his speed from 100 kmh to 60 kmh within a distance of 200 metres.  As the evidence eventuated the distance from the crest to the turn at the base of the rise was 240 metres.  He accepted that he could do an emergency stop in 200 metres but a non‑emergency stop would be done in 500 metres.  
Expert evidence
19		Geoffrey Colin Cocks, a civil engineer, was called to give evidence on behalf of the plaintiff.  He had been employed by the Main Roads Department between 1971 and 1989, and was currently a consultant to it.  He attended the accident site on 22 and 23 November 2000.  
20		He described the scene.  Approaching the crash site in the direction of travel of the truck, Hancock Road is straight for about 10 kilometres beforehand.  At the crash site, Hancock Road turns to the right at an angle of 43 degrees.  The radius of the curve on the road centre line is about 90 metres.  Hancock Road forms a junction with a gravel road, Tulloch Road, at the crash site.  Tulloch Road enters Hancock Road from the left.  The road is 3.7 metres wide but widens to 6 metres on the curve.  This is where the crash occurred.  Hancock Road has a bituminous sealed surface.  The distance from the crest of the rise to the crash site is 275 metres.  
21		Mr Cocks calculated that with a curve radius of 90 metres high trucks became unstable at speeds somewhere between 50 and 60 kmh when negotiating such a bend.  
22		His observations allowed him to conclude the following:
•	The area had an undesirable road configuration generally.  This included the gravel Tulloch Road entering into Hancock Road at the point it turned to the right ie there was an intersecting road entering at a tangent on the back of a curve.  
•	He found presence of loose gravel material from Tulloch Road present on the bitumen and this was likely to reduce skid resistance for a vehicle attempting to stop or slow down.  
•	The super elevation (the lifting up of one side of the road around a corner so gravity assists in a vehicle making a turn) was not developed to the appropriate level.  He used the guidelines for roads and road related structures as set out in Austroads (1993), "Rural Road Design Guide to the Geometric Design of Rural Roads" Austroads, Sydney.
•	Main Roads Department (WA) 1970 ("Road Design Manual : Rural" : Perth) recommends a bitumen surface with a 7 metre width on a curve.  The 6 metre width was substandard.  
•	There was incorrect spacing between guide posts installed on the curve in accordance with the Standards Australia 1994 "Manual of Uniform Traffic Control Devices", AS17 42.2.1994.  (There was no evidence as to whether these sign posts were present at the time of the accident or had been installed afterwards.  Ferguson did not notice any.)  He concluded that it was difficult to comply with the recommendations on numbers and spacing of the sign posts because of the entrance of Tulloch Road into Hancock Road.
•	Chevron markers should have been installed in accordance with Standards Australia (1994) AS3.4.4 to provide a significant visual clue to drivers of the presence of the curve.
•	The overall geometry of the road at the crash site was poor.  This included the fact the curve was sharp given the 10 kilometres preceding this curve was of flat to undulating terrain.  Without signage this creates the expectation of a gentle curve.
•	In circumstances of poor road geometry it is normal practice to install warning signs and there had been non‑compliance with the Australian Standard guidelines for warning signs.  
•	Road surface defects were generally within an acceptable range and unlikely to have contributed to the crash
23		Eric Martin Simms, a chartered consultant engineer, was called to give evidence on behalf of the plaintiff.  He attended the accident site on 16 March 2005.  He calculated the maximum safe cornering speed for a vehicle in a bend with a curve radius of 90 metres was 60.7 kmh.  He was of the view that gravel from Tulloch Road finding its way on to the bitumen of Hancock Road would have the effect of a vehicle's wheels losing contact and friction with the road surface and this would affect a vehicle being able to turn a bend at that speed.
Judge's statement of legal principles, the pleadings and the Judge's findings
24		The trial Judge set out the relevant legal principles governing the claim, which are not in dispute.  
25		The respondent's case alleged negligence and the particulars of negligence included allegations that:
"(ii)	Having regard to the nature and characteristics of the curve, the [appellant] failed to install a sign ahead of the crest warning drivers that it was not appropriate to approach and travel through the curve at a speed of greater than 60 kph.
…
(vi)	The [appellant] failed to install chevron markers at the curve so as to alert drivers to the severity of the curve.
…
(viii)	The [appellant] failed to install signs before and after the crest limiting the permissible speed in the general area to 60 kph."
These allegations were denied.
26		The Judge found that there was a foreseeable risk of injury and that the appellant owed a duty of care.  Her Honour accepted the content of the Cocks report, which stated that the constraints on road funding faced by local government were such that roads with substandard geometry could not all be reconstructed in the short term, and that it was common practice to leave reconstruction of such roads until such time as this was necessary for road pavement deterioration reasons and that it was normal practice to install warning signs and other traffic control devices ahead of sections of road with substandard geometry.  
27		The trial Judge found that what the respondent had to do in discharge of the duty of care was to install a "curve ahead/modified intersection/advisory speed" sign.  Her Honour noted that two weeks after the accident, such a sign was installed.  Her Honour found that this would have been a reasonably practical warning system that may have eliminated or minimised the risk of accident (at [52]).  
28		The trial Judge also found that the installation of chevron markers in the bend itself was likely to have created a visual clue of the severity of the bend for those cresting the rise 240 metres away.  Her Honour found that while there was some indication the road was to bend, the severity of the bend was not easily ascertainable, that it was easy to assume the road would go to the right but the severity of the curve was unannounced.  The trial Judge found that there was a foreseeable risk of injury to road users due to the faulty design, construction or maintenance of the road.  The appellant does not deny that it owed a duty of care to road users to exercise reasonable care to avoid foreseeable risk of injury or damage.
29		The question then was as to what a reasonable Shire had to do in response to the risk.  Her Honour found that a reasonable response required the installation of the warning signs and chevron markers.
30		The reference to the sign installed two weeks later was to an advisory sign, a photograph of which was put into evidence.  The sign showed a curve with a line indicating the presence of an adjoining road and beneath that sign a rectangular sign with the figures and letters "70 km/h".  The figures and letters were in black.  They were on a yellow background with a black border.  
31		No such signs were in place and no chevron signs were in place at the time of the accident and the trial Judge therefore found that there was a breach of duty.  
32		Her Honour then moved on to consider the issue of causation and said:
"55	Hunter Holdings must prove that some misconduct on the part of the Shire caused or materially contributed to the accident.  Romeo v Conservation Commission of the Northern Territory (1998) 192 CLR 431 at 482 per Kirby J.
56	It would have done so if it proved the failure to put up any warning speed limit signs and chevron markers had in some way misled Ferguson into thinking the road conditions ahead were better than they were.
57	I accept the evidence of Cocks insofar as it relates to the overall geometry of the road at the crash site being poor.  Whilst it was unreasonable to expect the Shire to carry out full scale reconstruction on a detour road it was not unreasonable, given its 'implemented' maintenance regime to install some warning of the difficulties a driver would face.  This would allow the manner of driving to be modified accordingly.
58	Ferguson was an experienced truck driver.  Like most motorists he relied upon road signs to direct his manner of driving and to alert him to any road conditions that could cause difficulties not immediately noticeable.  There was nothing at all to suggest he would not have observed and heeded an advisory warning sign.
59	Here the road presented, at the base of the incline, following a straight piece of road, a sharp bend as opposed to a gentle curve.  There was also a modified intersection with gravel likely to be present on the surface of the road.  It was clearly a situation warranting a reduction in speed.
…
61	I accept that a motorist travelling Hancock Road is likely to have been lulled into a false sense of security by the preceding 10 kilometres of straight road.  Whilst a curve at the base of the incline was apparent its severity was not.  There was no significant cue for a motorist of the need to take action in the manner in which a vehicle was being driven.
62	I find that Ferguson would have heeded a warning sign."
33		The trial Judge then found that damages amounted to $133,005.  Her Honour then turned to the question of contributory negligence.  Her Honour found contributory negligence on the part of the defendant.  She said:
"77	There is no denying Ferguson was an experienced driver.  He drove trucks for a living.  He drove long distances frequently.
78	He was travelling an unfamiliar road.  It was a secondary road being used as a detour.  It was not his usual designated route.  He was travelling a single lane.  He approached a rise in the single lane.  He did not have a clear view of the road ahead.  He did not slow his vehicle or move over.
79	Prior to arriving at the crest he was aware the road was likely to swing to the right at some stage.  He did not reduce his speed.
80	When he crested the rise he knew exactly where the road would curve to the right and he simply took his foot off the accelerator.  This did not affect his speed in any way.
…
83	I find that a reasonable and prudent driver in Ferguson's position, that is a driver of a tanker of dangerous chemicals in a long, heavy vehicle with a high centre of gravity on an unfamiliar road, would have substantially reduced his speed even before cresting the rise.
84	Even prior to reaching the crest he had a fair idea the road would go to the right.
85	It is obvious that the negotiating of any curve in these circumstances requires more than simply maintaining a speed of 90-100 kmh which is what happened once Ferguson first saw the curve.  Even on his own evidence, if he had braked earlier he could have substantially slowed the speed of the vehicle.  I find he was travelling closer to 100 kmh than to 90 kmh.  He had been travelling a straight, flat to undulating section with no traffic.  He stated he was travelling at around 100 kmh at a time very close to the accident.  He was not exceeding the speed limit but that does not justify the speed in all the circumstances.
86	I regard Ferguson's conduct as falling short of that which would be expected from him."
34		As a result, the trial Judge reduced damages by 30 per cent, to $93,103.50.  
Grounds of appeal
35		The learned trial judge:
"1	In ascribing the appellant's failure to install a warning speed limit sign as the cause of the accident rather than Ferguson's negligent driving, erred in fact, when the facts were and the learned trial judge should have found and given effect to the following.
1.1	Ferguson had visual clues as to the fact of and direction of the curve of Hancock Road and was not mislead as to the road conditions
1.2	Ferguson was aware of the severity of the curve 240 metres before the curve.
1.3	Ferguson could easily have brought the speed of the vehicle from 100kph to 60kph in less than 200 metres.
1.4	The road rose to a 'crest' at between 0.8% and 1.5% (i.e. 0.8m over 100m) and 'fell' at 2.6% (i.e. 2.6m per 100m)
2	Erred in fact and law in determining that the appellant's failure to install a warning sign and/or chevron markers caused or materially contributed to the accident.
2.1	Erred in fact in determining that there was no evidence to suggest that Ferguson would not have heeded a warning sign;
2.2	Erred in law in failing to give effect to the admission of Ferguson that he was aware of the severity of the curve 200 ‑ 240 metres prior to the curve.
3	Erred in law in determining that the appellant breached its duty of care to the respondent by failing to install a warning sign and/or chevron markers to indicate the severity of the bend in Hancock Road.
3.1	Erred in fact in determining that because Ferguson would have heeded a warning sign, the appellant owed a duty to install a warning sign near the curve;
3.2	Erred in fact and law in determining that the appellant ought reasonably to have known of the greater risk of injury to road users created by the detour onto Hancock Road;
3.3	Erred in fact and law in determining that the appellant should reasonably have been aware of the faulty design of Hancock Road prior to the accident;
3.4	Erred in law in failing to determine which aspects of the faulty design of Hancock Road the appellant should reasonably have been aware of prior to the accident;
3.5	Erred in law in failing to consider why the locus of the accident, as opposed to any other part of the road system under the care and control of the appellant, required a warning sign.
4	In the alternative to Grounds 1 to 3, the learned trial judge erred in fact in failing sufficiently [sic to] account for the negligence of Ferguson in reducing the respondent's award of damages."
Cross‑appeal
36		The respondent has cross‑appealed in relation to the contributory negligence determination made by the trial Judge.  The grounds of appeal read:
"1.	The learned Trial Judge erred in law and fact in making a finding of contributory negligence against the driver having regard to the bases of the finding of negligence against the appellant (the Shire) and the fact that the driver was driving within the speed limit (which  had not been reduced by the Shire by any advisory sign until after the accident) and without adequate notice of the sharp right hand bend in the road shortly after the crest (because the Shire had not erected appropriate signs until after the accident) after a 10 kilometre straight stretch of road.
2.	The learned Trial Judge erred in law and fact in reducing the award by 30% in that that reduction was excessive having regard to the bases of the findings of negligence and contributory negligence and the significance of the conduct of the parties in causing the accident/damage.
3.	The learned Trial Judge erred in law in failing to determine what speed a reasonable driver would have driven at over the crest, and what other actions should have been taken, and to consider what difference it would have made to the damage that was suffered, or in the alternative, failed to give any or any adequate reasons in relation to those matters."
37		The respondent also cross‑appealed on a fourth ground, complaining that the trial Judge had not awarded pre‑judgment interest.  That ground of appeal is conceded.
Appellant's appeal
38		It is logical to first consider ground 3, because it deals with the issue of breach of duty.  Grounds 1 and 2 then deal with the issue of causation, which does not have to be considered unless the appellant did breach its duty of care.  
Ground 3
39		Ground 3 involves a contention that the trial Judge erred in determining that the appellant breached its duty of care by failing to install a warning sign and chevron markers to indicate the severity of the bend in Hancock Road. 
40		The first particular to ground 3 contends that the trial Judge erred in fact "in determining that because Ferguson would have heeded a warning sign, the appellant owed a duty to install a warning sign near the curve".  In my opinion, the appellant itself errs in its understanding of the reasons for decision.  The fact that Ferguson would have heeded a warning sign related to the issue of causation, not to the issue of breach of duty.  The trial Judge held that the duty of care imposed on the appellant required the appellant to erect the warning signs and chevron signs, and that it had not done so.  That constituted the breach of duty.
41		The trial Judge then went on to deal with the issue of causation, which required consideration about whether Ferguson would, or would not, have heeded the warning signs and the indication of the curve by the chevron signs.  Particular 1 does not therefore support the ground of appeal.
42		Particular 2 contends that the trial Judge erred in determining that the appellant ought reasonably to have known of the greater risk of injury to road users created by the detour onto Hancock Road.  The appellant, in its submissions, referred to [47] of the trial Judge's reasons for decision when she said:
"I find it reasonable for the Shire to have foreseen that there would be an increased flow of traffic on this old, albeit in relatively good condition, secondary road.  I find it reasonable for the Shire to have foreseen that such traffic was unlikely to have been familiar with Hancock Road or, even, single lane bitumen roads.  It follows that it was foreseeable that there may be a risk of injury to road users, including Ferguson, as a result of faulty design, construction or inadequate maintenance of the secondary road."
43		The appellant then submits that there was no evidence presented at trial that the point on the Bruce Rock/Corrigin Road where the traffic was diverted onto Hancock Road was the responsibility of the appellant, or that the appellant was responsible for or aware of the fact that the traffic was diverted onto Hancock Road at the time of the accident.  
44		In my opinion, a diversion of traffic, where it was diverted and whose responsibility it was, are false or irrelevant issues.  It is true that the trial Judge did refer to these points, but any first‑time driver would ex facto not be familiar with the conditions on Hancock Road or be familiar with the deficient geometry at the site of the accident.  The reason why they were on the road does not have any relevance to the issue of foreseeability of the risk of injury to road users which the trial Judge was dealing with.
45		Particulars 3 and 4 contend that the trial Judge erred in determining that the appellant should reasonably have been aware of the faulty design of Hancock Road prior to the accident and erred "in failing to determine" which aspects of the faulty design the appellant should reasonably been aware of prior to the accident.  In my opinion, there can be no doubt that the faulty design aspects of Hancock Road are those which were observed by Mr Cocks.  These observations were recorded by her Honour at [36].  As her Honour noted, there was no viva voce evidence led by the appellant in opposition.  The trial Judge, by concluding that the reasonable response of the appellant to the defective geometry required the installation of warning signs and chevron markers, implicitly found that the Shire ought to have been aware of the deficient geometry observed by Mr Cocks.  Particulars 3 and 4 do not therefore support the ground.
46		Finally, particular 5 alleges that the trial Judge erred in failing to consider why "the locus of the accident", as opposed to any other part of the road system under the care and control of the appellant, required a warning sign.  Contrary to this particular, the trial Judge did consider and decide why the warning signs were necessary.  Her Honour clearly accepted Mr Cock's evidence about the defective geometry and then said at [61] that she accepted "that a motorist travelling Hancock Road is likely to have been lulled into a false sense of security by the preceding 10 kilometres of straight road".  There was no suggestion that it was not reasonable for traffic to travel at 100 kmh for the approximately 10 kilometres before the site and approaching the crest of the hill before the site of the accident.  Once a driver travelling at that speed reached the crest, the driver only had a few seconds - perhaps three seconds - to assess the situation and to adjust driving speed.  A slight miscalculation would have, and did have in this case, serious consequences.  The sharp curve was located only 250 metres beyond the crest and was therefore concealed as a hazard until the crest was reached.
47		In my opinion, therefore, the trial Judge did not err in concluding that a warning sign was required a reasonable distance before the "locus of the accident".
Ground 1
48		This ground concerns the issue of causation.  The ground assumes that the appellant owed a duty of care and that there was a breach of duty.  The ground involves a contention that the negligent driving by Ferguson was the cause of the damage, rather than the breach of duty by the appellant.  
49		Causation at law is concerned with the assignment or attribution of liability to one person to pay damages to another: March v E & M H Stramare Pty Ltd (1991) 171 CLR 506 at 509.  Legislation allowing apportionment and case law reflects a strong policy or tendency in favour of concluding that a plaintiff's negligent conduct should not sever the causal link between a defendant's negligent act or omission and damage to the plaintiff.  It is true, however, that there are cases where the plaintiff's conduct will result in a break in the causal link between the defendant's negligent conduct and the damage.  The cases where this is so are likely to be uncommon and the trial Judge in this case did not think that this was such a case.  
50		If the conduct of Ferguson was to be held to be the cause of the accident, then it must constitute a "supervening event" or, to use the English version of the Latin phrase often employed, "a new intervening act".  If the new intervening act constitutes conduct of the plaintiff (in this case the plaintiff's employee) in circumstances where there has been an admitted breach by a defendant, then the conduct must have been "unreasonable" before it can amount to a new intervening act.  See McHugh J in Medlin v State Government Insurance Commission (1995) 182 CLR 1 at 22 and Bennett v Minister for Community Welfare (1992) 176 CLR 408 at 428 per McHugh J; Chappel v Hart (1998) 195 CLR 232 at [93] per Kirby J and M'Kew v Holland & Hannen & Cubitts (Scotland) Ltd [1970] SC (HL) 20.  In M'Kew, the defendant's negligence had caused an injury to the plaintiff's left leg.  The plaintiff subsequently attempted to descend a steep staircase without a handrail and without adult assistance in the normal manner and received a severe fracture of his ankle.  This action was held to be unreasonable and to sever the chain of causation.  As Mason CJ said of this case in March v E & M H Stramare Pty Ltd at 517:
"The decision may be explained by reference to a value judgment that it would be unjust to hold the defendant legally responsible for an injury which, though it could be traced back to the defendant's wrongful conduct, was the immediate result of unreasonable action on the part of the plaintiff. But in truth the decision proceeded from a conclusion that the plaintiff's injury was the consequence of his independent and unreasonable action."
51		This ground of appeal contends that Ferguson had visual clues as to the fact and direction of the curve of Hancock Road and was not misled as to the road conditions, that Ferguson was aware of the severity of the curve 240 metres before the curve, that Ferguson could easily have brought the speed of the vehicle from 100 kmh to 60 kmh in less than 200 metres and that the road rose to a "crest" at .8 metres over a 100 metres and fell at 2.6 metres per 100 metres.  
52		In my opinion, this is not a case where Ferguson's conduct could be said to be unreasonable.  The corner where the accident occurred was located over the crest of a hill following a long stretch of road where travelling at 100 kmh was not said to be unsafe or negligent.  Nothing before the crest of the hill indicated that there was a curve in the road, save that Ferguson thought it might go round to the right because of the wheat bins.  When his vehicle came over the crest, it turned out that there was a sharp bend.  Travelling at 100 kmh, Ferguson had less than three seconds to respond to what he saw ahead of him and to slow down.  What was not known to Ferguson before he could see over the crest, was that the curve was sharp, that the geometry of the curve was substandard, and that it was unsafe to travel at more than 60 kms per hour around the curve.  The breach by the appellant in failing to erect relatively inexpensive signs to warn drivers of the need to slow down materially contributed to the accident.  It is the case, as the trial Judge found, that Ferguson did not respond quickly enough once he was presented with the corner, but in my opinion it cannot be said that his driving was so negligent as to amount to a new intervening event which broke the chain of causation which flowed from the appellant's failure to erect signs which would have had the effect of warning Ferguson in sufficient time for him to begin slowing even before the crest of the hill.  Ground 1 should be dismissed.
Ground 2
53		Ground 2 is a ground concerned with causation.  The contention is that the failure to install the warning sign and the chevron markers did not cause, or materially contribute to, the accident.  That is a very difficult argument to sustain.  In Bennett (supra, at 420), Gaudron J said in the case of an omission, questions of causation are answered by reference to what would or would not have happened had the omission not occurred.  Her Honour then said (at 420 ‑ 421):
"And although it is sometimes necessary for a plaintiff to lead evidence as to what would or would not have happened if a particular common law duty had been performed, generally speaking, if an injury occurs within an area of foreseeable risk, then, in the absence of evidence that the breach had no effect, or that the injury would have occurred even if the duty had been performed, it will be taken that the breach of the common law duty caused or materially contributed to the injury.  However, the question whether some supervening event broke a chain of causation which began with or which relates back to an omission or a failure to perform a positive duty, is one that can only be answered by having regard to what would or would not have happened if the duty had been performed.  It is only by undertaking that exercise that it is possible to say whether the breach was 'still operating', or, continued to be causally significant when the harm was suffered."
54		It is necessary to bear in mind that a plaintiff's evidence, given after the event, that certain action would have been taken if the negligent omission had not occurred, must be scrutinised with care.  In Commissioner of Main Roads v Jones, Callinan J at [83] noted that, in Rosenberg v Percival (2001) 205 CLR 434, he had counselled against too ready an acceptance of a plaintiff's evidence in those circumstances.  Nevertheless, the evidence of the plaintiff about what they would have done if there had been a warning sign is relevant evidence, and in this case the trial Judge held that, as an experienced truck driver, Ferguson would have paid heed to the sign.  There was no other evidence which contradicted that evidence.  In my opinion the trial Judge did not err in her acceptance of Ferguson's evidence.
55		The appellant's submissions concentrated very much on the existence of the curve, and the fact that this must have been observed by Ferguson as he came over the crest of the hill, but the Cocks report listed deficiencies other than the curve itself, and it was the combination of these factors which led to the accident.  All that the respondent had to show was that the fact as complained about materially contributed to the failure of the vehicle to stay on the road.  In view of the fact that the Cocks report was not contradicted by any other evidence, it is clear that all of the factors, having been accepted by her Honour as relevant, were factors which contributed to the accident.  While the existence of the curve may have been obvious, the deficient camber was not so to first time drivers on this road.  
56		In my opinion, her Honour did not err as alleged in the grounds of appeal.
The respondent's cross‑appeal and ground 4 of the appellant's appeal
57		The respondent contends that the apportionment of 30 per cent against the respondent was excessive, and contends that the trial Judge erred in failing to determine at what speed a reasonable driver would have driven over the crest and what other action should have been taken, and to consider what difference it would have made to the damage that was suffered.  There is a complaint that inadequate reasons were given in relation to these matters.  The appellant in ground 4 contends that the 30 per cent apportionment was materially inadequate.

58		In my opinion the trial Judge, in the paragraphs of the judgment referred to above ([77] to [80] and [83] to [86]), gave adequate reasons for her decision on apportionment and they reveal no error.  It was not necessary for her Honour to make a finding about the speed at which a reasonable driver would have driven over the crest.  Her Honour found that the negligence of Ferguson was in not slowing his speed at all.  His speed was just one of the factors involved in the complex of events which led to the accident, and the matters referred to by the trial Judge justified the finding of contributory negligence.  
59		In my opinion the 30 per cent reduction in the award of damages was an appropriate reduction in the circumstances related by her Honour.
Orders to be made
60		The appeal should be dismissed.  The cross‑appeal should be dismissed save that the judgment should be varied to provide for prejudgment interest.  The parties should be heard as to the amount of such interest.
61	BUSS JA:  I agree with Pullin JA.  I have some additional observations, however, on the learned primary Judge's determination in relation to contributory negligence.
62		The learned primary Judge's conclusion that the respondent's employee was guilty of contributory negligence involved findings that he had failed to exercise reasonable care in driving the vehicle and that his behaviour constituted a "departure from the standard of care of the reasonable man":  Pennington v Norris (1956) 96 CLR 10 at 16.
63		An assessment of a person's culpability, for the purposes of apportionment, requires a consideration of the relative importance of the conduct of each person who has caused the damage.  The whole conduct of each negligent person in relation to the circumstances of the accident must be subjected to comparative examination.  See Wynbergen v Hoyts Corporation Pty Ltd (1997) 72 ALJR 65 at 68.
64		A finding on a question of apportionment, as between a defendant who has been found to be negligent and a plaintiff who has been found guilty of contributory negligence, is a finding upon a "question, not of principle or of positive findings of fact or law, but of proportion, of balance and relative emphasis, and of weighing different considerations.  It involves an individual choice or discretion, as to which there may well be differences of opinion by different minds": British Fame (Owners) v 
MacGregor (Owners) [1943] AC 197 at 201.  It is well-established that such a finding, if made by a Judge, is not lightly reviewed.  See Podrebersek v Australian Iron & Steel Pty Ltd (1985) 59 ALJR 492 at 494.
65		In the present case, I am satisfied that the learned primary Judge's process of reasoning and conclusion, in relation to contributory negligence, do not reveal an error of fact or law.  A reduction of 30 per cent against the respondent was within the applicable range, although, in my opinion, at or towards the bottom of that range.