AN INQUEST into the collision that killed four popular teenagers has heard the last of the evidence, including expert opinions on the speed at which the truck involved was travelling.
Proceedings into the tragic deaths of Abby Ezzy, Brett McKenzie, Nicholas Nolan and Max Thorley in 2008 resumed yesterday.
The final witnesses yesterday presented their evidence during proceedings at the Brisbane Coroners Court, with differing opinions over the speed at which the truck was travelling at the time of impact having been heard.
Expert witness Dr Robert Casey, a mechanical engineer, told the court it was his opinion the truck was travelling at between 104kmh and 101kmh at the time it collided with the Honda the teenagers were travelling in.
He said his findings were reached using data obtained from the truck's engine management system, which highlights at which points the truck braked and when and by how much it decreased speed.
When questioned over a fellow witness' testimony that the truck was travelling at 89kmh at time of impact, Dr Casey said he trusted his own findings more.
Dr Casey said there were indications the truck was travelling at 107kmh "seconds before impact" and said there were signs of slight braking by the truck seconds before the two vehicles collided.
Forensic investigator Sergeant David Stocker also took the stand yesterday, offering some contradictory evidence to that of Dr Casey. Sgt Stocker told the court he attended Warwick to investigate the accident some 10 months after and it was his opinion the truck was more likely travelling at 89kmh at the time of impact.
He said data which showed the truck slow from 89kmh to 72kmh fairly quickly was likely due to the impact.
Evidence presented to the court yesterday highlighted that there were no skid marks at the crash site to indicate heavy braking, despite indications the truck had at one point slowed 8kmh in a matter of seconds.
Expert witnesses from yesterday's proceedings were unanimously of the opinion that it was McKenzie who was in the driver seat.
Dr Casey said he believed Ezzy and Thorley were both seated in the rear of the vehicle and Nolan was in the front passenger seat.
He added that his conclusions were reached by analysing the positions of the teenagers in the vehicle and elements such as seat belt marks.
The inquest will continue this week, with findings expected to be handed down by the coroner in April.