Road surfaces examined at inquest
ROAD safety and cost-efficiency of various road surfaces were examined yesterday as an inquest continued into what caused the deaths of six people in three separate crashes on the Bruce Highway south of Gympie.
Asphalt surfacing expert John Patane was called to present his review of reports undertaken by Department of Transport and Main Roads and Queensland Police, focusing yesterday on the crash that claimed the lives of Mark Hamilton, Rachel Purdy and Corey Whitmore on September 4, 2008.
The court heard how questions were raised about the safety of various road surfaces in wet weather conditions.
Mr Patane explained to the court that while open grade asphalt was considered “top of the range” (depending on rainfall intensity) in regard to its safety in wet weather, it had a much shorter life span (five to 10 years) than stone mastic. However, in dry weather, stone mastic asphalt was better in terms of skid resistance and had the advantage of having a much longer life span (10 to 15 years).
In determining what surface is used where, Mr Patane said the department typically took “a whole of life sort of analysis and what has been the history of that site”, adding that crash history also helped determine what sort of resurfacing should be placed there. He thought stone mastic asphalt was a very good product and able to keep roads at a satisfactory condition, and “extend that budget a bit further…”
Asked by counsel assisting, Andrew Wallace, if money was a consideration when assessing what surfacing to use on roads, Mr Patane replied that safety was first and efficiency was second.
Mr Patane did acknowledge that the crash history of that stretch of the Bruce Highway seemed particularly high but could not see any trends based on data contained in the reports he’d reviewed.
He acknowledged that the traffic volume was “quite high for a two lane road” with some 14,900 vehicles a day on average using that stretch of highway, with a 20 per cent commercial vehicle content (three tonne and over). Standing on the side of the road, he said, you would expect a vehicle every 4.2 second in either direction. Asked if he considered that a high volume of traffic, he replied “yes”, adding that such a high volume of traffic on a two-lane road meant a high chance of conflict with an opposing vehicle.
He pointed out that was why DTMR had instigated a full bypass of the area. Asked by Mr Wallace how much attentiveness was needed by drivers using that section of the highway, he replied, “...a high level of attentiveness when driving that section of road.”
Gary Ryan, a vehicle inspection officer with Queensland Police Service also presented his findings on the mechanical inspection of vehicles involved in the crash.
Mr Ryan said while the Isuzu pantec was mostly “demolished” he determined it was in a satisfactory mechanical condition, however its brakes, while not defective, were operating below optimum performance. His opinion was that a combination of factors, (such as it being close to unladen and wet road conditions) could have affected the performance of the vehicle.