A possible sequence of projects and related operation changes over the next 20-30 years. Note I've just plucked 5 year increments out of my backside, in reality, it'd be far more refined.
I'm using all known NDP projects (except for South-East fast tracks that appeared in latest release of NDP) with a bit of freelancing on my behalf on MARL and WRP - hopefully that's obvious as per below.
Key construction/project milestones:
MM1 construction out to 2025.
SRL1# construction from 2022 out to 2030.
MARL1^ construction from 2022 out to 2030.
CLR **** construction from 2026 out to 2030/32.
GHS*** construction from 2025 out to 2030.
WRP1* construction from 2025 to 2030.
MARL2^ construction from 2030 out to 2035.
MM2a** construction from 2030-2035/40
WRP2* construction from 2030 out to 2035.
SRL2# construction from 2030 out to 2040.
MM2b** construction from 2035/40-2045/50.
What each of the projects will be under this scenario:
# SRL1 new line from Southland to Box Hill.
# SRL2 new line from Box Hill to Airport.
^ MARL1 includes a [heavily] reconfigured Sunshine, new junction/pair Sunshine-Albion and then new track along Albion corridor and up into an underground station at Melbourne Airport.
^ MARL2 includes extending the tunnel at Melbourne Airport directly west and then taking the pair on the surface beyond the airport land to the Sunbury line just north of the Calder Freeway then quad track to Sunbury & Sunbury station reconfig.
* WRP1 includes works any works still required at Sunshine not carried out by MARL1 project (i.e connecting any new tunnels or platforms created but not immediately used after MARL1 starts ops), quadruplication Sunshine-Deer Park-Melton & includes electrification of Melton [current pair that goes through stations with platforms - new pair bypasses stations], proper Deer Park flying junction, electrification Deer Park to Wyndham Vale.
* WRP2 includes new electrified surface track Sunshine-West Footscray, short 2-3km tunnel under Footscray [no station, just an underground bypass] surfaces just west of Maribyrnong river, connects to redundant Sunbury (post MM1) pair - direct path to SX via North Melbourne.
** MM2a = Third side of West Werribee triangle & Wyndham Vale goes to 3-4 platforms, quad track West Werribee junction to Werribee station (so GHS gets the faster pair), Newport-SX tunnel via two Fishermans Bend station sites, duplication of Altona Loop.
** MM2b = SX-Clifton Hill/Merri tunnel.
*** GHS = Geelong High Speed, quad Werribee to Newport, upgrade track/signaling for 200kph speeds Newport-North Shore.
**** CLR = City Loop Reconfiguration sees Northern and Caulfield Loops turned into a through-route/track pair. New flyovers at North Melbourne to separate Upfield [Wallan] from Craigieburn, other minor-ish track reconfig for [Wallan]-Upfield-Glen Waverley, an extension of Upfield to Wallan including quad track Roxy Park-Craigieburn (only Craigieburn would have a set of platforms), electrification etc.
Key operational changes every 5 years (see opening disclaimer).
Pakenham/Cranbourne-Sunbury (MARL1 - basic off-peak and weekend service: 4TPH for Pakenham/Cranbourne, 2 TPH terminate at West Footscray, 6TPH continue on to Sunbury).
Pakenham/Cranbourne-Sunbury/Airport (MARL1 - basic off-peak and weekend service: 6TPH for each branch, paired with another at the other end, i.e Pakenham-Airport and Cranbourne-Sunbury etc)
Craigieburn-all stations to North Melbourne-Flagstaff-Melbourne Central-Parliament-Richmond-South Yarra then all to Frankston and vv. (CLR - basic off-peak and weekend service: 6TPH)
[Wallan]-Upfield-all stations to North Melbourne-Southern Cross-Flinders Street-Richmond then all stations to Glen Waverley and vv. (CLR - basic off-peak and weekend service: 6TPH).
Southland-Box Hill (SRL/Brand new, driverless/automated basic off-peak/weekend service: 10-12 TPH)
Geelong & suburbs - Werribee - Newport - Footscray - Southern Cross (GHS - basic off-peak and weekend service 3TPH, 3 TPH in peak (with another 3TPH going via RRL as per recent announcements)
Melton all stations to Sunbury and then via MM1. (WRP1 - basic off-peak and weekend service: 4TPH terminate at Westall/Dandenong)
Wyndham Vale all stations to Sunbury and then via MM1. (WRP1 - basic off-peak and weekend service: 4TPH terminate at Westall/Dandenong).
Ballarat all stations to Melton express to Sunshine then via RRL to SX. (WRP1 - basic off-peak and weekend service: 1-2 TPH).
Laverton all stations via Altona Loop & Williamstown to Newport then all stations to City via Footscray. (WRP1 - basic off-peak and weekend service 4TPH for both Laverton & Williamstown).
- MM1 pair would have a basic off-peak and weekend: 4 + 4 + 6 + 6 = 20 TPH service on the west at this point some would probably terminate at Westall or Dandenong rather than send everything out to Pakenham/Cranbourne.
- Sunbury-Pakenham could be a good pairing, Sunbury gets 10TPH in peak now and taking into account the larger trains in 2030 keep it at the same frequency, probably balances well with Pakenham. Airport-Cranbourne could be 6TPH but extra Cranbournes might originate at West Footscray (taking West Footscray-Cranbourne to 8 TPH (6 coming from Sunbury). Melton/Wyndham Vale - keep peak frequency the same as off-peak until WRP2 - 26 TPH in peak until WRP2.
Geelong & suburbs - Werribee - Newport - Fishermans Bend - Southern Cross (MM2a - basic off-peak and weekend service: 3 TPH, in peak 6 TPH - i.e all Geelong trains now mix with Werribee Newport-SX [same stopping pattern in this section] which, long term, is a very good idea for Fishermans Bend and developing it / hooking Geelong directly into it)
[Wyndham Vale]-Werribee all stations to Newport (express route) - Fishermans Bend - Southern Cross. (MM2a - basic off-peak and weekend service: 6 TPH).
Wyndham Vale all stations to Sunshine, switch to new WRP2 pair express all the way to North Melbourne-Southern Cross (WRP2 - basic off-peak and weekend service: 6 TPH).
Melton all stations to Sunshine, switch to new WRP2 pair, express all the way to North Melbourne-Southern Cross (WRP2 - basic off-peak and weekend service: 6 TPH).
Bendigo/Swan Hill/Echuca services run to Sunbury then divert via MARL stop at Melbourne Airport, Sunshine switch to RRL pair then express to Footscray and then Southern Cross (MARL2/WRP2 - basic off-peak and weekend service 2 TPH - peak 4-6 TPH [i.e some Kyneton or Castlemaine short-runners as well as main Bendigo and beyond services]).
Pakenham-Sunbury & Cranbourne-Airport (MARL2/WRP2 - basic off-peak service and weekend service: 6-8 TPH for each pair, half of the Cranbourne-Airport services continue on to Sunbury and terminate, half continue to terminate at the airport, Pakenham-Sunbury 6-8 TPH).
- WRP2 could probably kick off directly after WRP1 completes and the only major works are a short-ish tunnel and reconfig of tracks around the Maribyrnong River - definitely, a candidate that might only take 3 years, not 5 as per the basic outline I've used.
- 4 branches in the west (Airport/Sunbury/Melton/WV) all get a lot of room to breathe thanks to 2 branches coming off MM1 and onto the new WRP2 line.
- assuming "SRL" is just Southland-Airport (see below), the western sections are the standard metro services running WV-Deer Park-Sunshine sections that in 2035 (or earlier) have much more room to breathe/expand as needed as they'll run direct to the city and then out.
Southland-Airport (SRL2 Box Hill-Airport coming online - basic off-peak and weekend service 10-16 TPH/dependent on demand/managed differently due to it being driverless/automated).
Wyndham Vale-Werribee all stations to Newport - Fishermans Bend - SX - Parkville - Carlton - Fitzroy - Clifton Hill - Merri - all stations to Mernda (MM2b - basic off-peak and weekend service: 6-8 TPH) or maybe that other branch that's been on the cards for eons!