Had this in my mind for a while, and with some discussion of this issue on the South Rd thread, I thought I may as well sketch my ideas up and start a new Visions thread, so here you go...
With the recent additions to T2T and Darlington, a final, completed, uninterupted NS Motorway is finally becoming a reality. Much of the justification for this, at least for federal funding, relates to freight. As an eastern suburbs resident, I can say that pretty much all eastern states bound and sourced freight currently charges up and down Portrush Rd. Once more sections of the NS Motorway are complete, I am sure we will see this change to Cross Rd, as trucks aim to get on it and access the northern industrial areas quicker. It begs the question. how does DPTI see the SE Freeway and NS Motorway eventually linking up, if ever?
My personal thoughts are that the best option for this would NOT be Cross Rd. This is due to the mega land values and NIMBYness down this strip which would drag it out forever and blow a hole the size of the State Bank 1980's style in the Govt's coffers. The significant area needed for an interchange with the upgraded NS Motorway, which would be at Emerton train intersection, only further complicates and costs this solution. On the flipside, the benefits of the Cross Rd option are that it is the shortest route, and there are convenient options for truck arrester beds in adjacent Waite Arboretum and Urrbrae wetlands.
I believe a better option would be a route using Glen Osmond Rd, a tunnel under Glenside, Greenhill Rd, and Richmond Rd. I call it the Southern Connector (SOCR). Low-rez plain jpg here
...or much better hi-rez Google Maps version here (https://www.google.com/maps/d/edit?mid= ... vpacJcOfO0) where you can zoom in and click on each section or interchange to see detailed designs and annotated notes.
Clear benefits I see with the SOCR include:
- Land acquisition costs will be lowest, being mainly a strip along the upper section of Glen Osmond Rd, and some low value semi-industrial areas in Richmond and along Richmond Rd.
- It serves as more than just a link between SE Freeway and NS Motorway, but also as a key connector of traffic with the city and the airport, adding a very significant additional benefit to the economic analysis. This is not just for itself, but also for the entire linked system with a completed NS Motorway, and the city ring route, by leveraging additional use of those already completed assets (assuming it has been fully built by then).
- It is more likely to attract a greater proportion of federal funding, via the obvious freight and commercial benefits of linking in with the airport.
- Other than reducing the carnage that is Portrush Rd, it will also reduce load on the lower half of Glen Osmond Rd, enabling the community aspects of its development that the Council is seeking to proceed at Frewville/Glenside shops, Arkaba, the factory direct zone near Parkside Primary, coffee shops, etc..
- The low value semi-industrial triangle between Richmond Rd, South Rd and James Congdon Dr provides a convenient, relatively affordable and I think appropriately sized block of land for a chunky at-grade interchange that befits the connection of what would surely become Adelaide's two most utilized roads. Emerson certainly can't handle something like this. The closeness of Richmond and Anzac Hwy connections could be an issue, although looking at the new Darlington plans, and the closeness of the connections there, I no longer regard this as an issue with SOCR.
The downsides include no obvious arrestor bed zones, some tricky engineering at some of the interchanges (eg. Glenside with the creek, and Keswick with the railway). There will also be a parklands backlash via a small expansion of the width of the current Greenhill Rd corridor (I'm sure the gov't can find some land elsewhere to enable no net change).
What do you think? All reactions appreciated. Hoping SA can do something like this, or better somewhere else, to fill the missing link between our two marque road assets.
