Expert evidence: Traffic accident reconstruction reports and physical observations
16th Oct 2018
The plaintiff claimed for personal injuries sustained when his motorcycle collided with the rear of a horse float towed by the first defendant when the first defendant turned into the path of the plaintiff. The compulsory insurer (second defendant) alleged that the plaintiff was travelling too fast to be seen by the driver when turning, and that despite the traffic regulations the driver was not negligent – Brown v Holzberger  2 Qd R 639 and Sibley v Kais (1967) 118 CLR 424.
The plaintiff denied he was travelling too fast, primarily because he was ‘running-in’ a new engine and gearbox that had recently been installed in his motorcycle. The plaintiff sustained significant injuries, which also included his inability to recall the collision and a period leading up to it.
During the trial the plaintiff sought to rely on the report of Dr Kahler, but the second defendant objected.
‘429 Disclosure of report
A party intending to rely on a report must, unless the court otherwise orders, disclose the report – (a) if the party is a plaintiff – within 90 days after the close of pleading; or (b) if the party is a defendant – within 120 days after the close of pleading; or (c) if the party is not a plaintiff or defendant – within 90 days after the close of pleading for the party.’
To the extent that there was non-compliance with r429, his Honour excused it having regard to Allianz Australia Insurance Ltd v Mashaghati  1 Qd R 429 at -.
Justice Davis next turned to consider if the expert opinion was admissible. He found that expert opinion evidence is admissible if :
- there is a recognised field of study;
- the witness is an expert in that field;
- the opinion is based on the witness’s experience and expertise in the field; and
- the opinion evidence is probative of a fact in issue.
Justice Davis noted that in Queensland there is no recognised field of expertise of ‘traffic accident reconstruction’, but that the science of engineering is a recognised field, and to that extent an expert opinion based on engineering science would be admissible, subject to relevance. His Honour noted the limitations of this because problems arise ‘when there are unknown variables or assumptions so that the opinion cannot be said to be properly founded in the field’ . Justice Davis noted the limitations of expert evidence in traffic accident cases generally – Fox v Percy (2003) 214 CLR 118 and Anikin v Sierra (2004) 79 ALJR 452.
Relevantly, because the plaintiff could not recall the collision and his speed leading up to it, Dr Kahler included in his report some photographs of the roadway leading up to the collision area and intersection area. His Honour accepted that the photographs were relevant but found that the opinions were not based on science and it was open to the Court to draw its own conclusions :
‘These opinions are, with respect, not truly based on any science. They are simply conclusions which are drawn from physical evidence. No science or expertise is identified as the basis upon which the conclusions are drawn. The Court is in as good a position as Dr Kahler to consider the evidence and draw conclusions as to the movement of the two vehicles and of Mr Brown in the accident. The objection was properly taken and the evidence was excluded.’
Next, Justice Davis considered the document ‘A guide to road design part 3: Geometric design’ included in Dr Kahler’s report considering reaction times of drivers. His Honour excluded it because reaction times of drivers are ‘significantly undermined by the variables in any particular case’ .
Many of the other conclusions of Dr Kahler were excluded either by concession or by rulings by his Honour because the opinions were not based on the science of engineering, but assumptions drawn from the physical evidence, which Justice Davis found the Court was in as good a position to assess as the expert .
David Cormack practised as a solicitor for ten years before being admitted as a barrister in 2003, initially as In-House counsel for WorkCover Queensland. In 2009, David moved to the Private Bar and is briefed on personal injuries, occupational health and safety, industrial relations, employment law, mental health, mediations and restorative practices. David is a contributor to The National Work Health and Safety Law and Court Forms, Precedents & Pleadings Qld (Insurance; Discontinuance & Dismissal / Principles & Practice) subscriptions (LexisNexis). David maintains a web page and blog, providing newsletters to subscribers and has launched a free ‘App’ for calculating future losses of income on the 3 and 5% actuarial Tables, together with superannuation. Recreationally, David enjoys cycling for charity events and competing in kayaking. David volunteers with the Wynnum Redlands Canoe Club. David practices pro bono restorative justice via the Sycamore Tree Project with Prison Fellowship Australia (QLD).
The views and opinions expressed in these articles are the authors' and do not necessarily represent the views and opinions of the Australian Lawyers Alliance (ALA).