A number of alternative alignments are being discussed for a massive tunnel project proposed for Australia. A new tunnel is being proposed as part of the US&1.93 billion (A$2.5 billion) Great Western Highway duplication project. The link is intended to improve transport between Sydney and the western side of New South Wales State.
However, the latest proposal for the project is for the construction of two tunnel stretches in NSW passing through the Blue Mountains, instead of a single tunnel section. The proposal for a single tunnel to connect Lithgow and Penrith would result in the driving of one of the longest road tunnels anywhere in the world.
As it stands, the Great Western Highway duplication project will still require the building of a tunnel bypass stretch as well as another tunnel section to replace an existing bridge.