Tayside Police officer Neil Robertson told a trial that he thought excessive speed was the reason Edinburgh student Euan Tennant lost control of his sports car.
PC Robertson told Perth Sheriff Court that he reached that conclusion after establishing there was nothing on the road surface which could have caused Tennant to skid out of control.
He told the jury that the accident could have been “exacerbated” by Tennant’s lack of experience as a driver. He was being supervised at the time by his student girlfriend Laura Campbell, who died in the crash.
Tennant was driving a 21-year-old Toyota MR2 which he had owned for two months when he lost control and spun before smashing into an oncoming Ford Explorer 4x4.
PC Robertson said: “The main contributory factor was that the driver of the Toyota lost control of the vehicle, whereby it crossed into the opposing lane and collided with the Ford.
“There were no marks to indicate where it lost control. Statements indicated it was being driven at an inappropriate speed for the road and weather conditions.
“The driver’s lack of experience was likely to have exacerbated the situation. The driver said he felt the initial loss of control and touched the brakes.
“CCTV evidence indicates the driver was previously exceeding the speed limit. In my opinion I would say it has been driven at an inappropriate speed for the conditions.
“Tyre adhesion has been lost and therefore control has been lost. The safe speed to negotiate that bend has been exceeded and control has been lost and not regained.”
PC Robertson told the third day of the trial that tests showed that 47 miles per hour was the speed at which a car would start to lose grip on the bend, give or take ten per cent.
Tennant, who was studying alongside Miss Campbell at Abertay University at the time of the accident, told officers he believed he had slowed to between 40 and 45 miles per hour as he took the bend.
The trial had earlier heard Tennant’s description of the moment he lost control of the sports car and “broadsided” into the oncoming car at speed.
Tennant told police: “I am a learner driver. I am normally supervised by my girlfriend of two years, Laura Campbell. She has been driving for about five years and supervises me.
“It was raining - but not heavily - and the wipers were on. The road was wet and quite mucky from farm traffic. As I was about halfway round the corner I felt the back end twitch so I touched the brakes - not hard - then just lost it.
“It went, totally went. The back end came round, turning the car in an anti-clockwise direction. There were two cars coming towards me. I missed the first car, but then went on to hit the second one, a 4x4.
“It was Laura’s side that hit the 4x4 then it ended up facing the way we had come from. I immediately got out of the car and was calling Laura.
“She was ... making noises so I tried to get to her. I put my hand on her. The police, ambulance and fire brigade were there very quickly and I was moved out of the way to let the fire brigade get to Laura.
“Laura wasn’t able to speak to me at any point.” Tennant wept and put his hands over his face as this was read to the jury. “I believe the rain and the mud were to blame.”
The jury have been told that student Laura Campbell, 22, died as a result of the impact on the A93 north of Scone, Perthshire, on 22 September 2010.
Architect William Normand had earlier told the jury that Euan Tennant’s vehicle made a “ferocious impact” as it slid sideways down the wrong side of the road into his own car.
Tennant, 22, of York Place, Edinburgh, is alleged to have caused the death of 22-year-old business studies student Laura Campbell by driving carelessly on 22 September 2010.
Tennant denies that on 22 September 2010 he caused her death by driving carelessly and at excessive speed in Perth, and on the A93 Perth to Blairgowrie road near Scone.
He denies losing control of the car and colliding with Mr Normand’s vehicle, causing fatal injuries to his girlfriend and injuring Mr Normand and his passenger Paul Hirst.
The trial before a jury and Sheriff Michael Fletcher continues.
Laura, from Blairgowrie, was a former pupil at fee-paying Kilgraston and Craigclowan schools, and had just begun the third year of a business studies degree when she died.