The Badgerys Creek airport is the sole Sydney transport or land use project to receive increased funding in the federal budget.

Prime Minister Malcolm Turnbull emphasised his keenness to be involved in major urban initiatives at the release of his cities policy last week. But in the first budget under his prime ministership, much of the new money flowed to the bush, in the form of a commitment to an inland freight rail line and loans for dams and water projects.

For Sydney, the budget's transport priorities remain mostly unchanged from those of former prime minister Tony Abbott, who helped kick along a number of major road projects.

Of the new money, about $115 million will be spent in the next two years on preparation works for the Badgerys Creek airport, to be operational by the middle of the next decade.

Of that, $26 million will be spent designing a future rail link to the airport. The federal government has not said it would pay for a rail line to be running to the ariport when it opens, but that it would help plan for a future link.

But Mr Turnbull has intimated his government would be interested in supporting other urban rail projects in western Sydney.

There might be scope for the Prime Minister to announce an initiative along these lines in the coming election campaign. Any support, however, may have to be in the form of an investment, similar to the government's sponsorship of the national broadband network.

Last week Mr Turnbull announced $50 million would be set aside to help states prepare business cases for transport initiatives with the private sector. He also said the federal government needed to "stop being an ATM."

On the evidence of Tuesday's budget, he seems to be making good on his word.

Apart from the funding boost for the airport, the rest of the money flowing through to Sydney and NSW transport projects has already been announced.

That includes $5.6 billion to duplicate the rest of the Pacific Highway, a project scheduled to finish in 2020. It also includes $2.9 billion for road works around Badgerys Creek airport, $1.5 billion and a $2 billion loan for Sydney's WestConnex motorway, and $412 million for the NorthConnex motorway under Pennant Hills Road.

About $2.1 billion to support the Sydney Metro rail project, Parramatta Light Rail, and other transport initiatives under a scheme to encourage "asset recycling" has also already been announced.

But the budget also includes a $594 million injection of equity into the government-owned Australian Rail Track Corporation to help build the Inland Rail proejct.

This project, a freight rail line, would connect Melbourne to Brisbane. There are no dates as to when the 1700-kilometre line may be built.

"We know that an inland rail link will help to integrate domestic markets and bring global export markets closer to home," Treasurer Scott Morrison said.

"This is particularly important to leverage the benefits of our export trade agreements for Australian agriculture," he said.

The budget also includes a $2 billion loan facility to be spent on dams, pipelines and aquifer projects. The Deputy Prime Minister and Agriculture and Water Resources Minister, Barnaby Joyce, said a focus of the loan facility would be projects that produce affordable water and were economically and environmentally sustainable.

The loans would have concessional terms but would need to be repaid over 10 years.

"Water infrastructure is sorely needed across the country as we transition the economy away from mining towards more diverse sectors," Mr Joyce said.