Photo © 2009 AAP One/Dave Hunt

P-plate drivers in NSW should be subjected to a curfew on Friday and Saturday nights, an auditor-general's report says.

The report into young drivers found that deaths had halved during the past decade, following the introduction of a three-stage graduated licensing system.

But to further reduce the toll, NSW Auditor-General Peter Achterstraat wants P1 provisional licence holders to be banned from driving between 11pm and 5am on Friday and Saturday nights.

The Audit Office of NSW also wants the policy implemented by the end of June 2012, with the possibility of imposing a curfew at other times.

"The high level of crashes of young people at night could be a combination of factors including lack of adult supervision, lower visibility, fatigue, increased independence and risk taking," the report said.

It also calls for P1 licence holders to be banned from carrying more than one passenger.

Fatal crashes among young drivers has halved since July 2000, when a three-stage graduated licensing system was introduced.

The first phase requires 120 hours of on-road driving experience over at least 12 months.

Novice drivers also have to be on red and green P-plates, known as P1 and P2.

Novice drivers who repeatedly lose their licence should be subjected to psychological testing from the beginning of 2013, the report said.

Mr Achterstraat said that while the Roads and Traffic Authority had advised him there was no clear evidence psychometric testing worked, he believed problem drivers needed to prove they had the right attitude.

"It may well be that if you've lost your licence, you want it back again - you've got to pay for your psychometric testing and you've got to prove you're entitled to drive on the road," he told reporters on Wednesday.

"You should do an attitude test to see if you have the maturity to drive a car."

The report also showed a huge disparity between regional NSW and Sydney when it came to pass rates for getting a licence, which the auditor-general wants the RTA to review.

Young drivers under 26 make up 16 per cent of the driving population but are involved in a quarter of fatal crashes and almost 40 per cent of alcohol-fuelled crashes.

"There's a small minority of revheads and hoon boys who seem to think that they're the only people on the road," Mr Achterstraat said.

Learner drivers being supervised by their parents were the "safest drivers in the state" but became risk takers when they gained their P-plates he added.

Mr Achterstraat wants the government to consider raising the speed limit for learner drivers from 80km/h to 90km/h after six months to ease the transition to unsupervised driving.