The underground connection between Flinders Street Railway Station and the new Metro Tunnel station of Town Hall is certainly underway and gaining momentum. Leaving the Town Hall Metro Station the underground corridor connects to Flinders Street Station via the existing Degraves Street Underpass.
This is a great solution for changing between stations as that corner of Swanston Street and Flinders Street is quite busy for long periods of time. These photos show the path from Town Hall to Flinders Street.
If only many of the existing stations in the CBD can connections to major buildings via underground links such as those in Sydney and other locations like Hong Kong. One comes to mind being the now closed Spencer Street underpass that was heavily used and great for avoiding the traffic on Spencer Street. Closing this was a very bad idea.
Another opportunity would be a connection underground between Melbourne Central and RMIT, Melbourne Central and the State Library of Victoria also connecting to the large complex of the Queen Victoria Building.
I believe there will be an underground link between Library Metro Station and Melbourne Central but details have not yet emerged.
Metro tunnel is so very valuable to the city it should be extended and connected to the metro tunnel 2 between Clifton hill and Newport. Trains from Geelong could run between there and Epping. The city needs lot more of this investment.
Should be underway from a planning phase. Can they use the current boring machines from metro tunnel 1 and just keep building after planning the route.