The good news is that revenue from the sale of housing built on the 21 square km of new ‘land’ created above the trenches in the inner-city of Melbourne, Sydney and Brisbane by HSR would be enough to pay for the whole capital cost of HSR, FFR from Melbourne to Brisbane and the housing in the first 5 years of construction.
These estimates are based on conservative housing prices. Higher prices would cover possible higher capital costs. The revenue would also contribute to building housing in new regional cities over HSR stations.
Revenue from sale of regional housing for 10m of the 24m population increase, instead of more people living in major cities, may cover the cost of building the new cities during the next 40-50 years, as well as cost of the housing. This growing cost will be born as population doubles whether HSR is built or not. The question is where people will live. The choice is to preserve liveability or destroy it.