[U/C] M2 North-South Motorway

[TorrensSA]

There's extra width available at the old brickworks, I think a tunnel portal there until James Congdon Drive. A cheaper section from James Congdon to Anzac Highway, to get back some of the tunnel costs. The tunnel would be 3km and the cheaper next section 1.5km. A lot of properties would need to go though. From Anzac Highway to Tonsley it's 5.5km and who knows. So I think an extra bridge over the Torrens would be needed.

[SBD]

Nothing needs to happen at the river other than knock over a few buildings and block a side street off. Once the buildings are gone the corner can be eased via the new land.
I imagine the motorway will be pushed to Jervois Ave.
I'm pretty sure there is enough room for 3+3 on the existing bridge.

If the N-S Motorway consumes all six lanes over the bridge, then a new bridge would be required somewhere else for local traffic, including access from the north to Thebarton and Torrensville, and from the south to Welland and Hindmarsh. I think the motorway needs to be either above or below the existing bridge and river unless the shopping centre can be sacrificed to widen the road to the west..

[claybro]

Nothing needs to happen at the river other than knock over a few buildings and block a side street off. Once the buildings are gone the corner can be eased via the new land.
I imagine the motorway will be pushed to Jervois Ave.
I'm pretty sure there is enough room for 3+3 on the existing bridge.

And what of the cemetery?

[rev]

Nothing needs to happen at the river other than knock over a few buildings and block a side street off. Once the buildings are gone the corner can be eased via the new land.
I imagine the motorway will be pushed to Jervois Ave.
I'm pretty sure there is enough room for 3+3 on the existing bridge.

If the N-S Motorway consumes all six lanes over the bridge, then a new bridge would be required somewhere else for local traffic, including access from the north to Thebarton and Torrensville, and from the south to Welland and Hindmarsh. I think the motorway needs to be either above or below the existing bridge and river unless the shopping centre can be sacrificed to widen the road to the west..

No it doesnt. South Road Grand junction road intersection, you can no longer continue north on the surface road.

They could make the bridge section of motorway 2/2, bring the regular South Road right up to the cemetery boundary without a footpath with 1 lane up to West Thebby road.
And on the other side use the landscaped area of the brickworks to cut through where some of those houses are now and connect with the surface road out there.
But then you have the west thebby hotel and council community centre and a heritage listed bomb shelter.

What I hope they're doing is identifying what can go and what can't, with an eye on most of it going. Then again a long suburban tunnel would be great.

[bits]

If the N-S Motorway consumes all six lanes over the bridge, then a new bridge would be required somewhere else for local traffic

There is nothing local to access between T2T and Brickworks, so why do you need a local road?

[bits]

And what of the cemetery?

The cemetery stays exactly where it is. Accessible from a dead end Adam Street.

[Goodsy]

surely the tunnel portal would start back here. only need to acquire the one business

[SBD]

surely the tunnel portal would start back here. only need to acquire the one business

I wonder if that is the place for either a tunnel under the Torrens or a higher elevate motorway over it. In either case, perhaps that is why the Urban Stone place wasn't acquired for T2T. Perhaps it wasn't needed for the planned remainder under Weatherill and Mullighan. We don't know the Marshall/Knoll plan (but suspect it involves a long tunnel if they can pay for it). I get the idea that Malinauskas/Koutsantonis don't like the old plan, or they would be pushing to have it underway and claiming the credit because Labor thought of it.

[claybro]

surely the tunnel portal would start back here. only need to acquire the one business

That location makes sense for a tunnel entry in this section. The road is already lowered, and a tunnel from here through to Mile End would avoid all of the issues through Thebarton.

[ChillyPhilly]

The River Torrens would prove a significant challenge for a tunnel.

[Goodsy]

The River Torrens would prove a significant challenge for a tunnel.

I think there's enough space to get under the river

[SBD]

The River Torrens would prove a significant challenge for a tunnel.

I think there's enough space to get under the river

The first tunnel under the Thames in London was completed in 1841. If they could do that then, I'm pretty sure the Torrens would be no real barrier.

[ChillyPhilly]

It's more the steep decline required to get under it. Probably a gradient not suitable for a motorway.

[SBD]

If the N-S Motorway consumes all six lanes over the bridge, then a new bridge would be required somewhere else for local traffic

There is nothing local to access between T2T and Brickworks, so why do you need a local road?

I admit I don't know the area well. There looks like a residential area in West Hindmarsh and an industrial area against the Torrens in Welland. I was guessing that access to/from those from the south was via the South Road bridge.

I also imagined that the industrial area along West Thebarton Road might be accessed from the north via that bridge, but perhaps it is accessed by Port Road. Businesses north of Ashwin Parade and residences south of it would also currently use South Road to go north I expect.

[SBD]

It's more the steep decline required to get under it. Probably a gradient not suitable for a motorway.

How deep is the T2T trench? How deep would the floor of a tunnel under the Torrens need to be?

Just eyeballing it as I drive through, I doubt a tunnel would need to be much more than twice as deep as the trench, but I accept that hasty glimpses could be deceiving.