Mobile phone cameras catch hundreds of Illawarra drivers

And from Sunday, any more who get caught will be coughing up hundreds of dollars in fines.

The mobile phone detection cameras began operating in NSW on December 1.

The government had said the cameras would operate in warning mode for three months - with offenders getting a letter in the mail rather than a fine.

That ended on Sunday, and now offenders will cop a $344 fine and five demerit points.

As mobile phone use is among the double demerit offences, drivers caught during that period will get 10 demerit points (an unrestricted licence can accrue 13 points over a three-year period).

The Illawarra has no fixed detection cameras but, in the first three months of operation relocatable cameras were in the Illawarra for 24 days.

In that time, 170,142 vehicles were checked and 588 drivers were caught on their phones, receiving warning letters in the mail.

Across the state more than nine million motorists had been checked by the cameras with more than 30,000 warning letters being sent out across the state.

Centre for Road Safety executive director Bernard Carlon said using a mobile phone while driving increased the risk of a crash four times.

"Mobile phone detection cameras are being deployed statewide and transportable cameras are regularly moved to different sites across the network," Mr Carlon said.

"The number of days at each site will differ so that enforcement does not become predictable."

The cameras have some quite confused, with people falsely claiming they're at certain locations.

One example of many is the Boronia Avenue intersection at Windang; it features a traffic monitoring camera but people keep insisting online that it is a mobile phone camera.