"I had never heard such loud music; it completely changed how I drove," said the 17 year-old, who attends Colo High School. "You kind of get adrenalin; you feel like you are invincible because you ... show off."

With so much excitement and music, she drove faster than she intended.

Psychologist Bridie Scott-Parker describes this change as a typical "Jekyll and Hyde moment" that she has seen repeatedly among the young drivers after they get their P plates.

The experience terrified the cautious year 11 student enough that Tiarne has since avoided driving with groups of friends.

"I was shocked; I am not experienced enough to handle this," she said of that day back in June after she got her Ps. 

Tiarne was the first among her friends to get her P plates, after driving 120 hours with her parents and taking a private lesson with a driving school. Most of her driving experience was on rural roads, or back and forward between her home and her grandparents' house in Baulkham Hills. While her parents did their best to prepare their daughter, researcher Dr Scott-Parker says parents do not do enough driving at times and places where their children will drive by themselves once they get their licences.

Very little of Tiarne's 120 hours of driving experience happened on dangerous roads, the bulk occurred in daylight or early evening, and none was late at night or with friends and distractions like radio. Tiarne's parents gave her a Kia Rio for her birthday so she could drive the country roads to school and to her job at a local restaurant.

Dr Scott-Parker recommends that parents introduce their children to more risks in the last 20 hours on their L plates, and start playing a more passive role so that young drivers become used to only having "one set of eyes."

Once they have P-plates, parents should continue to drive with them. Even simple steps like sharing the family car, or making the new driver pay for petrol, helped to discourage risky behaviour:

"If they have to come home with your Camry with scratches down the whole side of the car, they are much more careful," she said.