Transport and Roads minister Andrew Constance this month confirmed the state government was considering removing the signage alerting drivers to the presence of fixed and mobile speed cameras.

Mr Constance cited Monash University research - which is not publicly available - found "up to 54 lives" per year could be saved if warning signs were removed.

"This isn't revenue raising, this is about saving lives," he said.

"Red light speed cameras reduce fatalities by 74 per cent. The road toll is up and it's time for action."

Mr Constance said he wanted speed cameras to carry the same threat as random breath testing - that people could be caught anywhere at any time.

But Mr Warren said warning signs served as alerts and deterrents to motorists, encouraging them to slow down.

He suggested the move was motivated by money and increasing the government's coffers.

"If a drive is speeding or runs a red light camera, then they should be dealt with accordingly," he said.

"But make no mistake, this move is not about improving the safety of motorists, it is simply a desperate cash grab from a greedy government."

The on-site signage is not the only way the government identifies speed camera locations for the public.

The Centre for Road Safety also includes a list of all speed cameras on its website.

Mr Constance's office declined to respond to Australian Community Media's questions as to whether that list would remain publicly available.

Read more: Speed camera warning signs crucial: NRMA

"The NSW government has a strong road safety record and that will continue to be the case," a spokeswoman for the minister said.

"There has been no change to government policy."

Speed camera locations are chosen because they are identified as a high-risk area with a history of severe crashes.

The latest speed camera review found there had been an 80 per cent reduction in fatalities at those locations and a 37 per cent reduction in injuries.

Mr Warren said Mr Constance should upgrade Appin Road if he "was serious and genuine about improving driver safety".

"There have been more than 30 deaths in the past 20 years on the notorious road, yet the government has failed to adequately address the issue," he said.

"Safety at the problematic intersection of Broughton Street and Moore Street also needs to be dealt with urgently.

"Centre for Road Safety records show there were 11 incidents at the intersection from 2013-2017 - and that figure does not take into account the number of minor accidents that were not recorded."

NRMA spokesman Peter Khoury also spoke out against the government plan.

He said the signs were "necessary and essential" as part of efforts to prevent road deaths.

"The warning signs act as a crucial education tool to alert motorists that they're driving in dangerous locations where people have been killed or injured and obviously what we want them to do is slow down," he told reporters in Sydney earlier this month.

There are three speed and red light cameras in Campbelltown and they are located at the intersections of Appin Road and Narellan Road; Narellan Road and Kellicar Road; and Moore Street and Broughton Street.