In four decades Sydney will be transformed into three distinct but connected cities under a plan headed by Lucy Turnbull.
Public transport will allow people in the eastern, central and western cities to live within 30 minutes of work and services.
The three cities will each have improved transport connections and will be linked to each other through a "technology-focused plan", NSW Transport Minister Andrew Constance says.
It includes proposals for a potential train link to Parramatta from Kogarah, plans to link Norwest and Parramatta by train and potential light rail extensions across Sydney, Parramatta and Newcastle.
The three-city concept was first established by the Aboriginal people, who saw Sydney as a land of three regions - the salt water region of the eastern harbour city, the muddy water country around Parramatta and the clear water country around western Sydney.
This plan, a collaborative effort between the NSW government's transport and planning departments and the independent Greater Sydney Commission, modernises the concept, Ms Turnbull said.