THE 33-kilometre WestConnex motorway, linking western Sydney with greater Sydney, will ease traffic congestion and boost jobs in western Sydney, Penrith state MP Stuart Ayres said on Tuesday.
"It's about easing congestion, creating jobs and connecting communities," Mr Ayres, who is also Parliamentary Secretary for Transport and Roads, said.
"It'll cost $11.5 billion and take about 10 years to complete."
He said WestConnex's construction would create 10,000 jobs, to be followed by the economic development it makes possible.
The WestConnex business case also envisages 25,000 new homes in the vicinity of the motorway.
The plan includes widening the M4 from Church Street, Parramatta, to Homebush Bay Drive, reducing travel time by about 40 minutes.
Mr Ayres said a toll of about $3 would help fund this part of the project, but no toll would apply to motorists travelling between Penrith and Parramatta.
The plan also includes building underground tunnels, estimated to divert 3000 trucks from Parramatta Road each day.
Mr Ayres said the project was made possible by the Abbott government which had committed $1.5 billion to it.
"But we don't think roads are the solution to all transport problems," Mr Ayres said.
"We also have the north-west rail line and the inner-west light rail projects.
"But by investing in WestConnex we're building for the future and giving people choice."