Underground Railway's in Sydney Post 2000

The most recent underground section of rail infrastructure that was built in Sydney is the Epping to Chatswood Rail Link, opened in 2009. This consists of 13km twin tunnels running with Stations at North Ryde, Macquarie Park and Macquarie University. The original plan was for a Chatswood to Parramatta link, however the NSW Government ran out of money to complete the project.

Finally, the North West Rail link, currently under construction, will eventually link up with the Epping to Chatswood rail link, creating the first major section of the Sydney Rapid Transit System. The Sydney Rapid Transit System will eventually link the North west, North Shore, CBD, Inner West and Bankstown Areas with Single deck metro style trains.

~ Cameron

The London underground

One of the many global transport examples that makes Sydney transport look like a dogs breakfast

Source

The London underground (also known as the tube) is considered the oldest rapid transport system in the world, which opened in 1863. It is also known as one of the first systems to use electric traction trains. What is every similar to the opal card in Sydney, Oyster card has been around since 2003 in London. The underground set a standard for the rest of the world in terms of intercity transport, having entrances available walking distance everywhere. On top of this the trains also arrive both very frequently and extremely consistently. If a train by chance is one minute late they will repeatedly apologize over the voice announcer for the duration of the service.

Source: Wiki
-Joseph