Initially rolled out in metropolitan areas, the cameras have slowly been making their way into rural NSW, catching drivers on their mobile devices and hitting them with $349 fines and five demerit points penalties.

Transport for NSW deputy secretary for safety, environment and regulation, Tara McCarthy says the research is clear when it comes to mixing mobile phones and driving.

"Research has found handheld mobile phone use while driving is associated with at least a four-fold increase in the risk of having a crash in which at least one person is killed or injured, texting increases the crash risk even further," she said.

"Simply taking your eyes off the road for longer than two seconds, doubles the risk of a crash, wherever a driver is on the road network - the message is simple - get your hand off it."

Unlike their speed camera counterparts, the new mobile phone detecting devices aren't signposted and use an algorithm to detect phone use in cars.

Transportable mobile detection cameras are being regularly moved from site to site across NSW, to ensure their locations aren't fixed, and drivers aren't warned in advanced.

More than 130,000 vehicles have been checked within the Mid North Coast region since March 1, which resulted in 428 penalty notices being issued.

Around one in every 307 drivers checked in the Mid North Coast region between March 1 and August 31 this year were issued a penalty notice, resulting in an offence rate of 0.33 per cent, higher than the state average of 0.23 per cent.

Millions of dollars in fines have already been issued, with one camera alone reportedly raising $6.4 million in four months, closing in on the $6.7 million in penalties the NSW police issued during the last financial year.

"Every cent from mobile phone detection camera revenue goes directly into the Community Road Safety Fund, which is used to fund important road safety programs such as road safety upgrades to our roads, education programs and school zone flashing lights," Ms McCarthy said.

"The NSW Government also makes significant additional contributions into the fund.

"NSW Police continue to enforce illegal mobile phone use and issue infringements as part of regular operations, those who think they can continue to put the safety of themselves, their passengers and the community at risk have been warned and will face the consequences."