The teen had put in hours of study on the road rules in preparation for the computer-based driver's knowledge test.

Read more: Protestors blast 'terrible decision' to approve Russell Vale mine

She'd even booked a test time a month earlier to get a date as close to her 16^th birthday as possible.

But when she arrived at the Service NSW office with her dad Dan, they were told the test had been cancelled due to the COVID lockdown.

The staff said the Harpers were called and told about the cancellation - a claim Mr Harper disputed.

"It's frustrating that they didn't tell us in advance so kids don't get their hopes up," Mr Harper said.

"They don't have many things to look forward to these days. It was really disappointing and upsets kids quite a lot."

The lockdown will affect not only any teen ready to get their learners, but also those who are eligible to get their Ps.

All driving tests to get P-plates have been suspended in Greater Sydney until the end of the month and until September 10 in regional NSW.

The computer knowledge test all teens must sit to get their learner's permit has also been suspended.

With the Greater Sydney lockdown already lasting several months and the possibility of it being extended into October, Mr Harper was concerned about the time it would take to clear out the backlog.

"The lockdown is possibly going to be extended for another month and then we have four months' worth of bookings to catch up on," he said.

"It's going to be quite a long time before these kids can actually sit their learner's tests, which does affect their job prospects in the future and will hold some back quite a lot - especially in regional areas where public transport wouldn't really be very helpful."

A Service NSW spokesman said plans for working through the backlog would be announced "as soon as it is safe and practicable to do so".

He confirmed the knowledge tests were still running - but only for those who had just lost their licence, not for those wishing to get their first one.

"Driver knowledge tests are only being conducted for essential purposes and where a computer test is the only requirement to having a licence reissued, such as if a test is required to support a customer's ability to earn an income or access essential services," the spokesman said.

In NSW a learner must hold their permit for 12 months before being able to progress to a provisional licence.

A Transport for NSW spokesperson said it was not an option to reduce that time to make up for delays to teens' getting their Ls.

"The minimum 12-month learner licence period is a key feature of the NSW Graduated Licensing Scheme and aligns with best practice in young driver licensing," the Transport for NSW spokesperson said.

"No change is currently proposed to this timeframe."

Transport for NSW said the licencing scheme was to help give a learner sufficient time to maximise their driving experience and develop the ability to perceive, anticipate and identify potential hazards and to respond accordingly.

The department was also investigating the possibility of moving the knowledge test to a digital platform - meaning teens could take the test at home rather than a Service NSW office.

The Illawarra Mercury news app is now officially live on both iOS and Android devices. It is available for download in the Apple Store and Google Play.