By Rayssa Almeida & Phil Pennington of RNZ

A woman whose son was killed by a driver on a restricted licence says adults must take the law more seriously to save young people from themselves.

Melissa* lost her son two decades ago.

A very experienced driver, he was going to visit his fiancé for dinner and was only a few metres from turning into her house.

"This young man came down a gravel road at an incredibly fast speed. And then he t-boned him and killed him", she said.

"The driver was young and inexperienced and having a passenger just made that much worse. Either they are not concentrating or they are playing to the gallery a wee bit," she said.

A Ministry of Transport study questions whether a stricter licensing system would protect young drivers better.

At the same time, the number of driver's licence offences police are recording has been plunging.

The number of infringements by teenagers on their learners or restricted licences has dropped by more than half since 2018, from 50,000 to 22,000.

RNZ is asking police to spell out how many offenders are being diverted and infringement notices waived.

Melissa was a high school teacher until recently and was aware that kids were piling into cars at the school gates each day with senior students driving who were not fully licensed.

"It's so much easier to take your friends with you. So it's never done with intent, with harm. But we are the adults, we are the ones that know what can happen, we are the ones that should be upholding the law and saving them from themselves", she said.

Overseas data shows a young driver having others in the car increases the risks of a crash from 100 to 400 per cent.

Ministry of Transport research shows drivers who have been caught in breach of their licence conditions have much more chance - of up to eight times - of having a crash.

They are four times more likely to have a crash resulting in death or serious injury.

Seventeen- and 18-year-olds on restricted licences are two to three times more likely to crash than fully licensed 16- to 27-year-olds.

More than a quarter of young drivers breach licence conditions, commonly carrying passengers when they shouldn't or driving after 10pm.

The ministry study concludes: "This raises questions about whether the changes to the ... graduated driver licensing system could better protect young drivers with restricted licences from crash risks."

It says the change could involve staying longer on a learner's licence or making it tougher to progress to a restricted.

The Driving Change Network is a non-profit group of more than 200 stakeholders who support driver education, training, and licensing.

National coordinator Wendy Robertson said the process to obtain a full license was not easy for some people.

"Some people in our community just can not afford professional driving lessons, or they don't have an adult with a full license to help them develop those skills that they need to have to be safe drivers".

She said driving education should start early.

"It should start at a secondary school level, so young people are getting good road service education before they get into a situation where they are getting tickets or been in an accident:"

The Ministry of Transport research says restrictions on night-driving and carrying passengers at the restricted licence stage are generally effective at reducing crashes.

RNZ has contacted the police about the drop in the number of restricted license infringements.

Restricted licence conditions

• Between 5am and 10pm, you can drive on your own.
  • Between 10pm and 5am, you can only drive if you have a supervisor in the front passenger seat
  • If you're driving without a supervisor, you can only take a passenger if they are:
  your spouse or partner (for example the person you live with as if you're married or in a civil union); a child who is financially dependent on you or your spouse (for example you're their parent or guardian) and who normally resides with you or your spouse
  your parent or guardian; relatives that live with you and are on a social security benefit; or
  someone you look after as their primary caregiver.

Be prepared to show evidence to a police officer if requested.

* Name changed to protect privacy.