In October, 19-year-old Thomas Scott-Dobie died when his Hyundai coupe collided with a Holden Rodeo utility four kilometres east of the West Cliff Colliery entrance.

A month earlier eight-year-old Brock Anderson died when a Holden Commodore driven by his father collided with a Subaru Impreza 10 kilometres south-east of Appin.

Brock's father Justin has started an online petition that blames "the disgraceful condition" of the road for his son's death and calls on the government to fix it.

"Our family will not let Brock become just a statistic for that road," Mr Anderson said.

"He would want us to be his voice, and that is what we are going to do."

The decision to launch a road safety study into Appin Road, from Campbelltown to Bulli Tops, follows a meeting in December between NSW Roads Minister Duncan Gay, Wollondilly MP Jai Rowell and representatives from Wollongong, Wollondilly and Campbelltown councils.

"Due to the recent fatalities, the Centre For Road Safety, with the support from Roads and Maritime Services, will be conducting a road safety review of Appin Road early this year," a spokesman for Mr Gay said.

"A timetable for that review is yet to be finalised."

However a review of speed limits, which change four times on Appin Road, was already under way, the spokesman said.

"The results and recommendations [are] anticipated to be available to the public by the end of January."

The spokesman declined to commit to funding all the recommendations from the road safety review, saying that "will be dependent on government priorities".

He said the RMS would soon start on a $300,000 project to install roadside barriers on Appin Road, west of Baden Powell Drive.

"These roadside barrier projects address the most common crash type on Appin Road, where vehicles run off the road and hit an object," he said.