I know you like trains but I cannot see a high speed train service. There will be just too many obstacles.

I can't boast about my arithmetic. I had to read the article twice. I liked the point about the old fashioned XPT. If the railway line was reasonably straight and flat, the poor old XPT could do it in six hours with change from the centre of Sydney to the centre of Melbourne.

I travel between Newcastle and Sydney fairly often and there arwe a lot of national parks, river valleys and hills that would be physical problems. Moving stations and railway lines within suburban areas will cause any amount of political heat, and expense.