Millions of dollars of new money has been earmarked for Sydney's west as the Turnbull government tries to make the most of building the city's second airport at Badgerys Creek.

NSW received just $1.5 billion of the almost $25 billion set aside in Tuesday's federal budget for infrastructure projects Australia-wide.

That led the state's treasurer to claim NSW was getting a "raw deal" before warming to other features of the budget.

Canberra had already committed $50 million for a business case into a rail line from St Marys to Western Sydney Airport matching the state government's contribution.

It's part of a broader $125 million over five years for projects under the Western Sydney City deal.

An extra $5 million was also allocated for a visitor and information centre on the airport site.

Nearly two-thirds of the money going to NSW - $971 million - is slated for a Coffs Harbour bypass, another $400 million was allocated for the Port Botany rail line duplication and $155 million set aside for a new bridge over the Shoalhaven River at Nowra.

The state will also have access to a $1 billion congestion fund "to support projects at a state level to fix pinch points and improve traffic flow and safety in our cities", Treasurer Scott Morrison told parliament.

"Our $75 billion, 10-year rolling infrastructure plan will continue - strengthening our economy, busting congestion in our cities, making rural roads safer and getting our products to market," he said.

It's unclear when those funds will start to flow through.

The Turnbull government also promised $25 million for a new monument at the Kurnell landing site of Captain James Cook and $3 million to develop additional cruise ship berthing sites in Sydney.

Tuesday's budget also confirmed NSW will get $4.02 billion for sale of its share of Snowy Hydro to the Commonwealth.

NSW Treasurer Dominic Perrottet appeared to have embraced a more positive tune on Tuesday evening, describing the budget as responsible, forward-focused and "a true Liberal budget".

It supported key NSW projects and would "help our state remain the beating heart of the national economy", Mr Perrottet said in a statement.

He praised the various funding handouts for NSW and said unlocking the state's share of the urban congestion fund would help deliver a 21st century road network for "Australia's only global city".

NSW opposition treasury spokesman Ryan Park accused Premier Gladys Berejiklian of failing to stand up for her state's taxpayers.

"NSW has been massively short-changed when it comes to important infrastructure," he posted on Twitter.

Mr Park said NSW was the highest taxed state in Australia.

Malcolm Turnbull on Monday denied NSW was being short-changed, pointing to the current and combined state and federal government infrastructure spend of $21 billion.

WHAT'S IN THE BUDGET FOR NSW:

* $971 million for a Coffs Harbour bypass on the Pacific Highway

* $400 million for duplicating the Port Botany rail line between Mascot and Botany

* $155 million for a new bridge over the Shoalhaven River at Nowra

* $100 million for Barton Highway

* $50 million for a business case into the first stage of the North South rail link from St Marys to Western Sydney Airport part of $125 million Western Sydney city deal

* $25 million for a new monument at the Kurnell landing site of Captain James Cook

* $5 million to build visitor and information centre at Western Sydney airport

* $3 million towards additional cruise ship berthing sites in Sydney

* $4.2 billion for the sale of its share of the Snowy Hydro