Parts of Sydney's rail network will be converted to a high-frequency, metro-style, single deck system, the state government announced today, while also committing to an eventual second harbour train crossing.

But the government performed an about-face on the North West Rail Link, declaring it would be a privately run shuttle between Rouse Hill and Chatswood, reversing an earlier pledge to run trains from the north-west all the way into the city.

Sydney's rail future

The decision means commuters travelling on the new rail line, and people travelling between Epping and Chatswood, will need to change trains at Chatswood for services to the city.

The Premier, Barry O'Farrell, and the Transport Minister, Gladys Berejiklian, made the announcements on "Sydney's Rail Future" at a press conference at Parliament House this afternoon.