Nothing wrong with the Bankstown Metro, long over due and the line will be significantly better off when done and may pull traffic away from the other lines. Miranda is another $4-5B and 5 years away.
The issue is dealing with the stations Lidcombe to Liverpool via Regents Park the right way and this should be 3 trains per hour via the Inner West, unfortunately for some services a platform change at Lidcombe is likely required until the Western Metro is up and running. Extension of the Metro to Liverpool should be a priority over Miranda for now as this will pull traffic off the Liverpool via Granville services. Likewise Miranda will pull traffic off current Cronulla services.
I disagree. Why has the government so far refused to release the business case if it's so sure of its viability? Like so much of the decision making by this secretive government, which completely ignores community feedback, I smell a rat. You only have to look at the compromises which have had to be made for the metro conversion of the existing line compared with what was originally intended. No straight platforms or re-alignment of tracks because of the narrow rail corridor and the consequent need to install gap fillers for starters. We have also yet to see the level of disruption which will be caused when the Bankstown Line is closed down for an extended period to complete the conversion and commissioning. The conversion of the Epping to Chatswood Rail Link was a walk in the park compared with what will happen with the Bankstown Line shutdown. They never thought this through from the very start, without even giving a thought to how it would impact on existing Sydney Trains' operations, which they are now belatedly trying to address. It's been planning on the run to achieve an ideological outcome.
An alternative strategy to free up capacity on the City Circle, which is allegedly one of the justifications for the conversion of the Bankstown Line, would have been to terminate the Airport Line at Central. It was after all the interloper as part of the failed privatised Airport Line. It could still be extended into the CBD from Central on a new alignment at a later stage, which is how it should have been in the first place.
I've expressed my view innumerable times that I am opposed to conversion of existing lines to metro as it compromises existing service patterns. The conversion of the Epping to Chatswood Rail Link as part of Metro Northwest is a case in point. One of the original justifications for this link as part of the broader Parramatta to Chatswood Rail Link, was to redirect trains from Hornsby on the Northern Line to the CBD via the North Shore and the Harbour Bridge, instead of the heavily congested Western Line via Strathfield. That option has now been cut off because of the metro conversion and Hornsby trains are now being redirected via Strathfield. The T1 Western Line suburban tracks between Strathfield and the North Shore Line through the CBD were already operating at their maximum frequency of 20tph and consequently the additional semi-express peak hour trains from Hornsby were forced onto the main tracks to terminate/start at Sydney Terminal. That's a downgrade in existing services in anyone's language.
Completion of Metro West has now been pushed back into the 2030's and apart from the Badgerys Creek Airport Link, it's doubtful whether any other metro lines will be completed sooner. That leaves a huge gap over multiple election cycles, spanning at least 2 decades. Covid-19 throws up another obstacle for future planning and it's anyone's guess what the outcome will be.
While it will obviously be some time before the metro now under construction could be extended from Sydenham as an interim terminus to Miranda, it is nonetheless an option which could be considered. That would have to be weighed up against other priorities. If the conversion of the Bankstown Line to metro proceeds, and that's still not a given, any further extension to Liverpool would be low on the list of priorities.
In the meantime, while Covid-19 will continue to have some impact on existing patronage, pinch points on the Sydney Trains' network have to be addressed when things get back to normal. If the Liverpool via Regents Park services are reinstated, which is the government's apparent preferred option, then I don't think a frequency of 3tph is sufficient, particularly during the peak. It should be 4tph at a minimum. The Inner West Line with its mixed stopping pattern has a current frequency of 14tph in the peak and a maximum of 16tph. It will be more when ATO is rolled out. That would allow for the possibility of retaining at least 2tph T2 starters/terminators at Parramatta. Although it's not ideal, this highlights the necessity for extending sextuplication between Homebush and Granville to allow stations in between to have direct access to Parramatta at a higher frequency.
The government's current rail strategy is flawed in focussing on metro expansion at the expense of targeted infrastructure upgrades to the existing network to address more immediate congestion issues. They may not be as sexy as a flashy new metro line, but they will give far more bang for your bucks at significantly less cost.