Long disruption for Upfield line passengers https://www.railpage.com.au/news/s/four-level-crossing-removals-among-program-of-winter-works.It is impossible to build anything on the corridor with the rail line below, it is far too narrow. Piers for the elevated structure are going smack in the middle of the corridor. It is not like other projects were rail lines can be slewed and a trench or piers built along side, then a week shutdown for a tie in.
I'm assuming it's easier and quicker to build without having a live railway line below, plus the low frequency and relatively few stations past Anstey make it easier to justify such a long shutdown.
Boardings are around 4000 people, its a big difference to Frankston & Dandenong. Plus you have the 19 & 58 trams that run parallel to the corridor.