There have been several proposals to develop an HSR line between Sydney and Canberra (via Sydney Airport and Canberra Airport) to link the cities and provide an effective second airport for Sydney. The line is proposed to continue to Melbourne, possibly via Melbourne Airport.
A range of proposals has been made to create a high-speed rail network between Sydney and Canberra, passing via Sydney Airport and Canberra Airport to link the cities and provide a practical secondary airport for Sydney. The route would then extend to Melbourne, potentially via Melbourne Airport.