<p>The New South Wales Government has promised an $8bn expansion of Sydney’s suburban rail network, including a new line linking the city’s northwest and the southwest.</p> <p>The expansion will take place over 15 years and will run from Rouse Hill to Leppington via the city.</p> <p>It will involve 13 km of new surface track and 25 km of tunnels, the government said.</p> <p>Initial spending will concentrate on acquiring the land corridors.</p> <p>The first stage of the project will be the construction of the line from Glenfield to Leppington, to be operational in 2012.</p> <p>The government said it will use a mix of budget funding, borrowings and private sector finance for the project. </p> <br />