With parking being such a nightmare in chadstone around special events like mothers day, christmas and even on weekends, it's obvious better public transport links need to be explored.
1) Train link. The closest stations to chadstone at the moment are Hughesdale (pakenham), oakleigh (pakenham), holmesglen (glenwaverly). Hughesdale is probably the closest within walking distance (around 1km). The others having bus links to chadstone. The location of these are sufficient enough barriers for people to continue driving to chadstone.
To rectify this barrier there are a few solutions:
1) Build a new station at chadstone shopping centre.
a) One possible solution would be to extend existing lines to Chadstone.
The glen waverley line can divert from east malvern station -> Chadstone -> Holmesglen. OR
The pakenham line can divert from hughesdale station ->Chadstone->oakleigh.
For political reasons, costing should probably be based on a subway rather than overhead lines due to local resident objections.
b) One could divert lines and bypass existing stations.
Going from carnegie station->chadstone->oakleigh and deleting murumbeena and hughesdale stations. Murumbeena and glenhuntly could then be served by extending the glenhuntly tram down neerim rd.
c) Create a north-south train line connecting hurtsbridge, belgrave/lilydale, alamein, glen waverley, pakenham and frankston lines. Chadstone could be just one stop in this massive investment. This will be the farthest reaching collecting passengers from the east and south east which are likely that people that drive to chadstone the most.
2) Tram links. The most obvious and shortest extension would be to extend the tram line from the city down waverley rd and turn right down chadstone rd with a super stop at chadstone shopping centre.
3) Bus links - A no brainer is to increase the frequency of bus links to train stations.