Infrastructure NSW has bagged the City Circle for being under utilised, which it is. Why is this so? Put simply there is not enough rolling stock to fill in all the paths. There is currently in the busiest hour at Central approaching the Town Hall leg of the City Circle 7:57am to 8:53am 15 trains made up of:
2 Bankstown via Lidcombe
7 South line via Fairfield
2 Bankstown via Sydenham
2 Ashfield all stops
2 Liverpool via Regents Park
The Infrastructure NSW plan would remove the ability to fill in the gaps with Bankstown via Sydenham trains. The only option would be to reverse the parts of Clearways which have been achieved and go back to using the "Illawarra Junction" near Macdonaldtown to achieve this - a move sure to reduce reliability. Ron Christie has slammed this aspect of the Infrastructure NSW plan particularly.
Currently, there are only a few impediments to putting more trains on the Bankstown and East Hills lines, which would fill up the City Circle. Better that this option is left in reserve for future growth.
The Infrastructure NSW report should be binned.