More than 120 schools will be built or upgraded across NSW as part of a $4.2 billion education spend in the next four years, while a further $38 million was promised locally to build roads.

In John Barilaro's first budget as deputy premier, he said schools in the Monaro would receive tens of millions of dollars to get kids out of demountable classrooms.

Queanbeyan East Public School, Karabar High School and Queanbeyan High School will be upgraded.

As part of the announcement, a new school was planned for the city to focus on special needs students.

The member for Monaro said the lack of special-needs facilities meant Queanbeyan children had to rely on schools in Canberra.

"We have a number of kids with disabilities that have to access schooling across the border," Mr Barilaro said.

"These upgrades will help provide the school facilities our community needs and deserves."

The Coalition government also announced $46 million would be allocated to regional and rural schools to focus on upgrading technology.

The assistant minister for education Sarah Mitchell was in Queanbeyan on Monday ahead of the budget and said overcrowding in government schools was a concern.

She said student numbers were due to increase by 21 per cent by 2031, which was about 164,000.

The budget included a $70 million Queanbeyan-Palerang Roads Package.

Included in this figure was $24.4 million for the continued construction of the Ellerton Drive Extension, but a further $38 million was given for new projects.

This extra cash will go towards the duplication of Old Cooma Road and for the remainder of Nerriga Road to be resealed.

The council hadn't expected the added cash for roads and was pleased by the funding allocation.

"When Queanbeyan and Palerang were merged, the need for funding for our road network was immediately apparent," administrator Tim Overall said.

Other projects that will be covered by the $70m outlay are the replacement of the Charleyong Bridge, upgrading the intersection at Tompsitt and Lanyon Drives and a new roundabout on the corner of Malbon and Molonglo Streets in Bungendore.

"Nerriga Road is an important yet unfinished link in our regions road network that has been overlooked by successive Governments for years," Mr Barilaro said.

"The poor state of the road is currently dangerous for tourists, residents, the local school bus run and freight companies and I'm so pleased this crucial project will finally come to fruition."

The projects are expected to begin this year with funding secured for ongoing road improvements into 2019.