Upon reading about Newmark Capital's intention to redevelop South Yarra's Jam Factory, my first thought was 'gee South Yarra station's going to be busy'.
Busier than it currently is in peaks, mind you.
The headline numbers are quite impressive: an end-value of $1.25 billion and 100,000 square metres of mixed-use space. 50,000 square metres will be new office space with floorplates up to 4,000sqm spread across 4 office towers up to 15 levels in height.
If approved, tenanted entirely and opened as planned, the 5,000 jobs that would exist on the site once the redevelopment is complete is not a figure to dismiss. The comments in relation to rethinking the lack of a Metro 1 stop at South Yarra have already begun and it's likely many 20:20 hindsight anecdotes will follow.
Given the likelihood the state government would revise its earlier decision to not include an interchange at South Yarra is slim at best, focus should shift to the existing interchange at Caulfield which will be the only point at which passengers from the Pakenham and Cranbourne lines will be able to interchange with a Frankston line service to get to South Yarra station.
Caulfield station is a relic of times gone by. The existing platforms and connecting ramps are subject to flash flooding like many other stations with the same design (looking at you Oakleigh), the track layout leaves much to be desired (and a lot of people thrown about inside the trains) plus trains are slowed right down to 25kph when they traverse the pedestrian subway which links the 4 platforms.
Ideally, Caulfield station would have a 5th platform added with a 1 track flyover at each end of the station to lift either the citybound Pakenham/Cranbourne track or the Frankston bound track over the other.
This would allow for same-direction trains from Pakenham/Cranbourne and Frankston trains to enter Caulfield on the same island platform - facilitating a seamless platform transfer between lines - and vice versa. Likewise, a secondary entrance build overhead with escalators and lifts would mitigate future flash flooding risks as well as provide an alternative to the pre-disability standards-era ramps.
Noting it is the second-best option compared to a full and proper interchange at South Yarra, the passenger interchange infrastructure and experience at Caulfield should be top priority, especially as more employment space is created in the inner suburbs further up the line.