The world-first mobile phone detection cameras in NSW have in their first week of operation nabbed more than 3,300 drivers breaking the law.

Key points: Sydney Harbour Bridge, Lucas Heights and Nowra were named as problem areas

Sydney Harbour Bridge, Lucas Heights and Nowra were named as problem areas A three-month grace period meant offenders were sent a warning letter in lieu of a fine

A three-month grace period meant offenders were sent a warning letter in lieu of a fine The NSW Roads Minister said Norway was observing the rollout of the cameras closely

The cameras were rolled out across the state at the beginning of this month, with figures released on Tuesday showing about 500 people were caught on average each day in just one week.

Over 773,000 vehicles were scanned in the first week across six different locations.

The Sydney Harbour Bridge and Lucas Heights in Sydney's south-west were named as particular problem areas, with 179 and 210 detections respectively over four days.

There were also 126 detections at Nowra, on the state's south coast.

NSW Roads Minister Andrew Constance said the early figures were disappointing.

"We really need people to understand that driving behind the wheel with a mobile phone is one of the most reckless and stupid things you can do," he said.

"We're the first jurisdiction in the world to do this.

"Let's just bed it down and take the community with us."

Mr Constance said countries such as Norway, as well as other states and territories in Australia, were watching the rollout of the cameras closely.

A three-month grace period is currently in place, meaning those caught by the cameras so far will be sent a warning letter instead of a fine.

From March, however, drivers caught using their phone while driving will received a fine of at least a $344 and cop a penalty of up to five demerit points.

Unlike speed cameras, the mobile detection cameras are portable and motorists are not alerted to their presence.

The State Government said independent modelling showed these cameras could prevent about 100 fatal and serious injuries over five years.

NSW Centre for Road Safety executive director Bernard Carlon said there was no excuse for using a phone behind the wheel.

"You're four times more likely to have a casualty crash, impacting on you or the families of other people," he said.

"Get your hand off it."