First Australia had the mining boom, then the east coast housing boom, now the nation's economic hopes are pinned to its biggest ever infrastructure boom.

Key points: State governments have committed tens of billions of dollars in their recent budgets to build transport infrastructure

State governments have committed tens of billions of dollars in their recent budgets to build transport infrastructure RBA governor Philip Lowe says it is "the right time" to borrow to build infrastructure, with interest rates at record lows

RBA governor Philip Lowe says it is "the right time" to borrow to build infrastructure, with interest rates at record lows Construction employment ended a downtrend, with the most recent May quarter figures showing jobs growth

In their recent budgets, state governments collectively splashed tens of billions of dollars on transport infrastructure and other public works.

Queensland's Government committed to almost $50 billion of infrastructure spending over the next four years, including $23 billion for road and rail.

Victoria's Treasurer said the state had $107 billion of state capital projects "commencing or underway", with a $27.4 billion "suburban transport blitz" the centrepiece of its 2019-20 budget.

The latest New South Wales budget dwarfs even that level of spending, with $93 billion earmarked for infrastructure over just the next four years, including $55.6 billion for road and rail, $10.4 billion for water, energy and housing, $10.1 billion for hospitals, and $7.3 billion for schools.

On top of that, the Commonwealth has re-committed to $100 billion of transport infrastructure spending over the next decade, including projects such as Sydney's second airport and a Geelong fast rail proposal.

Lowe wants even higher infrastructure spending

However, the Reserve Bank governor Philip Lowe has urged governments to spend even more.

"I've long been a very strong advocate for investment in infrastructure," Dr Lowe told a business audience at a speech last Thursday.

"I think now's the right time to do it — we've got the capacity in the economy and the labour force, and it adds to the supply capacity of the economy, so it increases the productive capacity of the economy over time.

"Right today the Australian government can borrow at the cheapest rate since we became a federation, with the 10-year government bond rate at 1.35 per cent and the government can borrow for almost 30 years at less than 2 per cent.

"So there must be some projects out there with risk-adjusted rates of return at 1.5-2 per cent."

The Commonwealth Bank's senior economist Belinda Allen said the benefits from infrastructure investment were two-fold.

"It provides the short-term boost to the economy through employment, through construction, through the spill-overs from that, but it also adds to the medium-term growth of an economy through improving productivity," she told RN Breakfast.

"That's where the real benefits from infrastructure come from, through better road, rail networks, improving travel times and allowing people to do effectively more in a day."

Infrastructure to soak up redundant home builders

While those efficiency benefits will take many years to deliver, as the new transport links are gradually completed, Bureau of Statistics figures appear to show some of the short-term employment effects are already being felt.

Reversing the trend of the past year, construction employment increased by more than 30,000 in the three months to May.

That saw jobs growth in the sector of about 7,000 over the past 12 months, which Ms Allen said was a sign the infrastructure boom was soaking up some building workers from the apartment bust.

"These quarterly job moves can be volatile but it does not show job losses given the falls in residential construction work done," she noted.

"There is a large amount of non-residential construction work being undertaken. Recent state budgets have also allocated additional funding for large infrastructure projects.

"We would expect this to limit any job losses from residential construction."

The weakest sectors of the Australian jobs market over the past year are now manufacturing (with nearly 50,000 jobs lost, although this was lower than in February), media and telecommunications (down more than 31,000) and finance and insurance (with more than 8,000 jobs lost).

The strongest sectors were professional and technical services (up by more than 87,000), education and training (up nearly 64,000) and public administration and safety (up almost 50,000, although this is much weaker than it was in February).

Separate ABS data show that strong jobs growth needs to continue to absorb a rapidly growing population, which increased by more than 400,000 people during 2018, or just over 1.6 per cent.