But why would you want to restrict it to running under main roads when you can avoid clashes with deep building foundations by planning a route in advance?Wayno wrote:i like normans approach of following the main road arteries - presumably helps avoid clashes with deep building foundations...
Cut and cover has its advantages, but it isn't necessarily cheap or easy. Unlike tunnelling, It would require pipes and cables to be relocated. There are water pipes (blue), sewers (magenta) and storm drains (red)...Norman wrote:Precisely. It would also be easy and cheap to implement, as cut-and-cover could be used.

...and in addition, there are gas mains, electricity cables and phone cables.
???North Terrace, Wakefield Street and Grote Street are all wide boulevards that would make implementing an underground easy. The westerly exit also provides an oppertunity to create a city loop, making best use of limited railcar resources.
How is putting the trains onto a big loop a good use of railcar resources?
The platforms are far too short for interstate trains.Adelaide Station can also be returned to serve interstate trains and diesel services,
A sensible location... but you've still got only two stations in the CBDwhile Underground lines use a station located next to the railway station just underneath the current tram stop. More on that later.