Tunnel trams @ Unley

At the recent Unley Council meeting (June 2016) there was healthy debate about the merit of underground trams (in a tunnel) under Unley Road; from Greenhill Road to Cross Road, a distance of ~ 2km.
Mayor Lachlan Clyne had publicly proposed consideration of underground trams.
Unley Council responded with a motion on notice that sought to publicly disassociate itself from the Mayor's proposal.

It was a healthy debate.

My argument against the proposal was as follows:

My costings, formulated by assistance from civil engineers, forecast a cost of $1.5b.
That cost may blow out to $2b within 5 years.
The new Sundrop solar powered salt water tomato farm at Port Augusta costs $180m. At that price we could build another 5-8 Sundrop tomato farms.
The proposed solar powered and thermal storage power station at Port Augusta will cost $1.2b. We could build another one and have $300m left over.
These project costs at Port Augusta put the proposed expenditure at tunnel building in Unley into perspective.
Unley Road would need to be dug out to a depth of 10-15m.
All of the underground services ... gas, water, sewerage, power, cables, optic fibre, drains etc would need to be replaced.
Unley Road would need to be closed for ~ 2.5 years. There would be no cars on Unley Road (no through traffic) and retail would be ruined. It would destroy all of the Unley Road shops.
It is not even a Council road. It is a State Government road and the State Government will determine where the trams run and the final design. At a cost of $1.5b for a tunnel, I am sure that the Government would prefer to inject funding into Arrium @ Whyalla to keep the steel maker afloat.

In brief, I didn't  support the Mayor's proposal of a tunnel under Unley Road.

The motion was lost.
So Unley Council has no formal or stated position on the matter.

Hopefully this proposal gets no more attention and quickly dies; perhaps symbolically buried under Unley Road; shoved down a manhole 🚽