Passenger services into Melbourne were suspended in early July after the NSW Government announced the border was to temporarily close.

The first service since the border re-opened arrived at Southern Cross station in Melbourne on schedule at 6.30pm on Wednesday, 10 hours and 50 mins after leaving Sydney at 7.40am.

The first service to depart Melbourne for Sydney was on Thursday.

Resumption of normal passenger services followed two days of safety trials, during which the trains completed their runs into and out of Melbourne without passengers.

To help maintain physical distancing, every second seat is being left vacant, and a spokesman for Train Link encouraged customers to plan ahead and book tickets early.

Other Covid measures include enhanced cleaning, and it's believed passengers are required to wear masks south of the border.

ACCELERATED TRACK REBUILD

Frequent travellers from Cootamundra to Melbourne should notice a smoother ride and more reliable service south of Albury, thanks to a massive program of accelerated track works.

The MP for Riverina and deputy PM, Michael McCormack, said this week work had been "fast-tracked" because coaches have been replacing trains for Victorian passengers since the XPT stopped running.

Mr McCormack said that although the line was still in use during border closure for freight, the reduction in passenger traffic meant the contractors, the John Holland Group, were able to accelerate their program of rebuilding the track during the border closure.

"The Australian Government is investing $244 million in the package of works to improve this major rail corridor," Mr McCormack said.

"We're now more than three-quarters of the way through construction thanks to the great progress we've made while trains weren't running.

"We continue to roll out this type of project nationwide under our $110 billion infrastructure pipeline, which is laying the foundation for economic recovery following the Covid pandemic."

The upgrade of the Sydney-Melbourne line started earlier this year, with more than 300 kilometres of tamping, mud hole removal works and drainage reinstatement now finished.

The project will also include works to upgrade an additional 20 rail bridges than previously foreshadowed, and renewing track turnouts at Seymour and Violet Town to improve ride quality and reduce delays for passengers on the line.

Victorian Minister for Transport Infrastructure Jacinta Allan said the work would make journeys on the line more comfortable and reliable.

Federal finance minister Simon Birmingham said the Australian Government through the Australian Rail Track Corporation would continue to back vital rail upgrades to boost services and generate economic activity across regional Australia.

"This is about keeping Australia moving and creating more jobs, with around 100 ongoing jobs created through the north-east Victoria rail line upgrade," Mr Birmingham said.

"Our investment in regional rail is boosting opportunities for local businesses including in design, construction and project management, while delivering lasting benefits for rail passengers and freight operators."

Senator for Victoria Jane Hume said the upgrade had been about "making the best of a bad situation" during the Covid pandemic.

Senator for Victoria Bridget McKenzie said more than 80 level crossings had been renewed and more than 50 rail bridges have upgraded, giving passengers a smoother ride.

"This will allow some temporary speed restrictions to be removed on the line, making services more reliable for passengers."