Here is my proposal for a considerably more cost-effective cross-town Outer Circle that would achieve most of the same objectives.
Outer circle 2 (may be used with attribution)
1. Footscray interchange
2. Newmarket interchange
3, Flemington interchange
4, Rushall interchange
5. Fairfield interchange
7. East Camberwell interchange
8. Riversdale/Willison (new combined station)
13. East Malvern interchange (with walkway to East Malvern and Jordanville stations)
15. Hughesdale interchange
16. Ormond station interchange (with underground walkway and travelators to Ormond station)
17. Elsternwick interchangeDescription and construction.
The Outer Circle would commence with new underground platforms and an underground railway departing Footscray station. Travelling underground it would emerge near the Maribyrnong River and cross using a new rail bridge. Diving underground again at Riverside Park cut and construction would see the line travel under Princes Highway and Racecourse Road arriving at a new Underground interchange at Newmarket.
Continuing under Racecourse Road the rail link would proceed underground to Flemington Bridge station with underground platforms. The line would then emerge to the surface on the right hand side of the existing Upfield line before spurring right under Sydney Road following the course of the old inner circle line. Past Sydney Road the line would be underground with cut and cover construction. The line would emerge to the surface with additional platforms at Rushall station before Skyrail to pass over Merri Creek and then next to the Hurstbridge line but underground (cut and cover).
At Fairfield there would be additional platforms for the new line which would then proceed underground, turn and follow the course of the old Outer circle line, reusing the old railway bridge to get across the Yarra River. This would require the construction of a new road bridge across the Yarra and having the railway travel under the freeway. Then, travelling at ground level the railway would travel along the old Outer Circle easement with a new station at Kew.
Cut and cover construction would be used along the old Outer Circle easement from there to East Camberwell where new underground platforms would be built (north/south). The line would pass under the Belgrave/Lilydale line and continue as the Alamein line does now using the existing stations along the line. Riversdale and Willison would be combined into a new single station.
After Alamein the line would proceed underground with cut and cover used along Poath and Chadstone Roads with a new underground station near Chadstone with an underground walkway linking to the Shopping Centre.
Continuing south the line would arrive at Hughesdale station with new underground platforms. The line would then continue underground south along Poath Road before curving right to follow the alignment of the old Rosstown railway but underground.
The line would then emerge and finish at new platforms at Elsternwick station.
This new line would provide cross-town access to all Melbourne's railway lines at a considerably reduced cost as much of the route uses existing or disused rail alighments. It also would provide access to Chadstone Shopping Centre.