This then led to a whole bunch of comments calling for more roads to be built because that will reduce congestion of course.
Those commenters who suggested more roads are necessary went the whole hog and asked for freeways. For example, comment 2 said simply "Build a decent freeway system" though what constitutes a "decent" system remains to be seen. Comment 6 asked for an "elevated highway from Greenhill Rd intersection with Anzac Highway through the parklands immediately west of the cemetery and Adelaide High through the outer west sector of the North Adelaide Golf No.2 with clover exits and entries East and West". Comment 49 was similar and asked for an elevated "South Road on stilts above current restricted south road. Make 3 lanes each way".
I think it is safe to assume that none of these people will live near these elevated freeways.
A few commenters bemoaned the MATS plan that was (thankfully) cancelled in the 1970s. Part of that plan was the proposed Modbury freeway which became the very successful north east busway. Parts of the plan have in fact been built, such as the Port River Expressway.
Two major parts of the plan led to its downfall I think. One was the Hills Freeway which would have connected the CBD with the start of the South Eastern Freeway. It would have cut through a number of eastern suburbs. The second was the Hindmarsh interchange. It consisted of a number of flyovers above each and in turn above the suburb of Hindmarsh. It would have been revolting.
A city does not need elevated highways to be economically viable. It may be nice for those people speeding along them to get home but the wider benefits are more questionable. I imagine people living underneath them would not be quite so enthusiastic. A comparison of Glasgow and Edinburgh reveals the difference as anyone who has visited the two cities will have seen. Edinburgh does not have any freeways running through it and it is doing just fine. Glasgow on the other hand is still suffering. There is a good post (with good pictures) on the War on the Motorist blog.
The fact is, building more roads does not solve congestion. There is not a single city in the world that has solved congestion by building more roads. There are some really well written studies that shows the effects of building more roads. Two particularly good ones are "Before and after opening of the M4 Motorway from Mays Hill to Prospect" and "Before and After the Motorway" by Michelle Zeibots.
Building yet more roads merely makes cars even more necessary because the alternatives slowly become impossible. Not being able to get around without a car then becomes a wider problem because people end up paying such a large portion of their income on running their car (or two).
We know it doesn't work. I would really like to us try something different.
Build it and they will come. From Wikipedia.