An ABC Fact Check last year deconstructed the government's argument that a single-deck system would have more capacity than double-deck services. In most large cities, a single-deck metro service, is used in the city centre, operating at short intervals. They make the least sense in suburban areas such as the city's north-west and south-west. Favourably comparing the Sydney Metro with projects such as London's Crossrail is misleading as the latter is a heavy rail line connecting the east and west of the city through the CBD.

The North West Rail Link, it turns out, was only the first piece of the puzzle - the first sign of the government's real plans for handing our public transport over to private operators. Like the North West Rail Link, tunnels will be too small to accommodate the larger capacity trains needed as Sydney grows.

It seems very recently that the government had us all scratching our heads over its plans to shut down and replace the recently opened Chatswood to Epping line for its private metro service and incorporate the line into the North West Rail Link. This line was only opened in 2009 for $2.4 billion, under the previous Labor government.

Despite the bloated price tag and the failed ambition of extending the line all the way to Parramatta, the Chatswood to Epping line is a good service. It works for people, especially those in the North Ryde and Macquarie Park industrial areas and students attending Macquarie University, linking them south to the CBD and north to Hornsby. It is well patronised and efficient, but the government wants to disassemble it - now, along with the Bankstown line - to make way for a privately operated metro.

Critics of the North West Rail Link have always said it marks the beginning of the privatisation of the Sydney Trains network. We have been advocating for the North West Rail Link experiment to be terminated at Epping and for any future rail lines to be built double-deck and part of the existing network.