Record infrastructure spending in NSW and Victoria is struggling just to maintain current assets, new figures show, as transport and other services groan under the weight of population growth.

The KPMG analysis of state and federal government capital expenditure shows of the 4 per cent growth in public spending on infrastructure, more than 3.5 per cent is needed just to cover depreciation and population growth, leaving a fraction for a "pure" net increase in stock.

Victoria has the lowest net increase of all the eastern states, courtesy of a population boom that has seen Melbourne become one of the fastest growing cities in the developed world at close to 3 per cent annually.

Transport is struggling to cope with population pressure. Credit:Paul Rovere

The headline figures of $80 billion being spent on new infrastructure over the next four years in NSW and $40 billion in Victoria - up to double the average of the previous decade - mask the daily struggle of infrastructure to keep up.