i live in aus. just to clear that up first.
we have to be 18 before we can even go for the test to get our license to drive alone. (im 18 now)
you can legally start driving at 16, if you have a permit and a licensed driver is in the car next to you.
now, i got my license when i was 16, have been driving quite a bit since then (as in, a couple of hours a week on average) in different places, time, weather all that shit, having lessons etc...
a few weeks ago, i almost got t-boned in an intersection that i go through regularly. it wasnt my fault, the guy ran a red, but when i realized it would have been both my parents getting hit, and only dad telling me what to do in that situation that stopped it happening, it scared the shit out of me.
i get my license in a few weeks, but by no means would i have been ready to drive alone a few years ago. i have friends who think its cool to do 100 in 60 zones ( im using km/h) and get plastered then do burnouts. another one of my (female) friends thinks revving the hell out of her manual before she moves off is the best thing to do.
by no means do i think anyone would be ready to drive on their own at 16. it comes from experience, common sense and listening from someone thats been driving for a long time who can give you some advice.