The NSW government's implementation of the cameras, which caught almost 100,000 drivers in a six-month trial earlier this year, has been designed to have an "anywhere, anytime" impact.

The cameras come without warning signs, typically used with red-light and speed cameras, and many will be portable so they can be easily moved and used on almost any road in the state.

Instilling the element of surprise by ditching the warnings signs is part of the government's effort to curtail the state's staggering road toll, which has reached 330 fatalities already in 2019.

When the legislation to implement the cameras was announced in October, Roads Minister Andrew Constance made no apology about forgoing warning signs.

"I want behaviour to change and I want it changed immediately," he said. "It's not about revenue raising; it's about saving lives."

The cameras will record the offence of a phone being "held by, or resting on, the driver of a vehicle".

READ MORE: Hunter MPs back mobile phone detection cameras

Drivers caught in the first three months will receive a warning letter.

Offences thereafter will result in a penalty of five demerit points and a $344 fine, or $457 in a school zone.

The detection system operates day and night and in all weather conditions, using high-definition cameras to capture images of the front-row cabin space of all vehicles.

The system uses artificial intelligence to review images and detect offending drivers. It also excludes images of non-offending drivers from further action.

Images the automated system considers likely to contain a driver illegally using a mobile phone are then verified by an authorised person.

The program will be expanded over three years, from 2019/20 to 2022/23, with a target of achieving over 135 million vehicle checks each year by 2022/23.

There will eventually be 45 fixed and transportable cameras deployed across the state. The program aims to reach over 95 per cent of the NSW population through a mix of metropolitan and regional deployments.

Centre for Road Safety director Bernard Carlon, who last month told the Herald the cameras would "absolutely" be used in the Hunter, said on Thursday mobile phones were one of the worst distractions for drivers.

"Driving is a complex activity; anything that takes your hands off the wheel, eyes off the road or mind off the driving task is dangerous, not just for you, but everyone else on the road," he said.

"Research has found hand-held mobile phone use while driving is associated with at least a four-fold increase in the risk of having a casualty crash, and texting increases crash risk even further.

"Simply taking your eyes off the road for longer than two seconds, doubles the risk of a crash."