IT'S the proposed highway that has Penrith residents up in arms.
While the Outer Sydney Orbital (M9) planned by the state government has the potential to introduce more jobs, more industry and reduce travel times, residents are less than enthusiastic about the new motorway.
Under the proposal, the highway could run from as far south as Wollondilly, via Camden and Penrith, and finish in the north-west and Hills district.
A group of residents have formed the Stop The Orbital and Rail Corridor action group.
Transport for NSW said the proposed motorway was needed to support Sydney's population which is forecast to grow from 4.3 million to 5.6 million people with an additional 625,000 jobs.
"Greater western Sydney will be home to more than half of Sydney's population," a Transport for NSW spokesman said.
"To support population and employment growth west of the M7 motorway, a north-south corridor is needed."
The state government has allocated $4.6 million in the state budget to identify and reserve the transport corridor.
Transport for NSW spokesman said planning was already under way for the project, but the timing of construction was yet to be determined as were the cost and financing options.
"Studies are currently under way to determine if the project will have any impact on communities in the local area, or whether there will be any impact on local properties," he said.
"Transport for NSW will look to minimise negative impacts on existing property."
Stop The Orbital and Rail Corridor member Lauren Taylor said the group opposed the proposed highway because it had many adverse affects on the community, particularly residents of Orchard Hills, Werrington and Claremont Meadows.
"Many residents will lose their homes, and thousands more will suffer 24 hours a day, seven days a week from the noise and air pollution from the truck-dominated M9 motorway," Ms Taylor said.
"We are concerned that the proposed corridor is to go through the critically endangered bushland at the defense establishment at Orchard Hills and the former ADI site, which is home to numerous threatened species."
President of the Western Sydney Conservation Alliance Geoff Brown said the proposed highway could affect suburbs from Badgerys Creek to north of Windsor Downs.
He said he knew of the proposed route after Mulgoa MP Tanya Davies responded to a concerned resident's question about the Werrington Arterial stage one project on her website.
"The local politicians are aware of the preferred routes," Mr Brown said.
"Tanya Davies talked of the M9 route early last year going through Claremont Meadows.
"And the council staff who we met yesterday [Monday] claim their map showing the orbital is just a random line on a map yet it lines up perfectly over Kent Road as per Tanya's 2013 comments.
"People are being treated as mugs."
Ms Davies said the project was a proposal.
"The Werrington Arterial stage one project has the potential to become the M9. However investigations are still under way and public consultations are yet to commence," she said.