HeapsGood wrote: ↑
Mon Feb 10, 2020 2:45 pm
Spotto wrote: ↑
Mon Feb 10, 2020 2:17 pm
Regency to Pym - 2019-22 (projected)
Torrens to Anzac - nothing
Anzac to Darlington - nothing
What do you think is a realistic completion date on the remaining part of the North to South Expressway if you had to guess it?
My rough prediction based on current progress... perhaps 2035? :p
Well the T2T Project upgraded a little under 4km of road in approx 37 months (3 years 1 month). The Torrens to Anzac section (stopping before Gallipoli Underpass) is around 4km; Anzac to Darlington is around 5.5km.
The Torrens to Anzac Hwy section (approx 4km) except for Don Bradman to Richmond Road, is nearly all residental, so other than a few cut-and-cover tunnels where necessary, a trench similar to T2T could probably be put there. I can't imagine the cut-and-cover tunnels would be too different to the road bridges (partially excavate, install pylons, install concrete beams, excavate fully) other than covering more distance. Between Don Bradman and Richmond Road is pretty dense with businesses, so the government could either bite the bullet and acquire all that land on both sides of South Road. Or maybe acquire only one side of the road and build a longer cut-and-cover tunnel; half(-ish) the acquisition cost, takes up a narrower corridor than a trench design, and lets businesses on one side of the road stay. Roughly comprable to the T2T Project, could take 3 years and a few months considering the fact that the cut-and-cover tunnels would probably add to the timeline.
Anzac Hwy to Emerson Crossing (approx 1.1km) could just be a simple ground-level motorway, but if they really wanted to excavate a trench they could. There might be enough room in the Gallipoli Underpass to squeeze an extra lane in both ways (definitely at the very least a 3-2 road) if the bike lanes (relocated to the surface) and stopping lanes are removed and the median is replaced with a typical concrete barrier which is narrower. Emerson Crossing is a necessary upgrade: run the railway underneath Cross Road the gates feel like they're more often down than up during peak traffic. Perhaps they could make do with somehow keeping the current overpass and building around it but I have no idea if that's even possible.
Emerson Crossing to Darlington (approx 4.3km) will likely be the most tricky part. Like Don Bradman to Richmond Road, it's lined with businesses and industry with more behind those with road frontage but it's a much longer stretch of road in addition to business further back from the road. Plus there's a whole shopping centre and a few clusters of big box stores which would be next to impossible to even bother acquiring.
Emerson to Darlington would probably only be solved with a deep-bored tunnel(s). But for the length of the road, if you're bringing in a TBM for one section you might as well just do the whole lot (9.5km). 4km is a pretty short stretch for what would be an extremely expensive TBM, Adelaide is a much smaller city than our east coast sisters. And (this is the public transport side of me coming out), if the ground conditions along South Road are similar to underneath the CBD, the TBMs could maybe be adapted to finally build an underground rail link for the Gawler and Seaford lines like the Melbourne Metro Tunnel. Get our money's worth out of the TBMs.