The price tag for Victoria's most expensive road had already hit more than $26 billion by the time the boring machines started on Monday but the people in charge are adamant the project is in on time and within budget.
Cost estimates for the North East Link have grown from $10 billion in 2016, to $15.8 billion in the 2017 business case and finally to $26.1 billion in December 2023.
The Albanese government came to the rescue of the mega project with an extra $3.25 billion in the May federal budget, lifting its total contribution to $5 billion.
Victorians have to fund the rest.
But, after years of talk, the project finally got underway on Monday with digging starting on the twin 6.5km tunnels between the suburbs of Watsonia and Bulleen.
The two boring machines being used were named after women's rights activist Zelda D'Aprano and neonatal pediatrician Gillian Opie.
And Major Roads Projects Victoria chief executive Duncan Elliot said the project was tracking on time and budget with the road expected to open in 2028.
But opposition transport infrastructure spokesman David Southwick criticised the government for focusing on naming the tunnel boring machines instead of keeping down the project's price tag.
"Who knows how much the North East Link is going to cost Victorians," he said.
"This is a good project that's been managed poorly."
The machines will dig up to 15 metres per day and up to 45 metres underground with Mr Elliot saying there would be little, if any, vibration felt by those on the surface.
"But just to protect any assets that are in areas where we are more shallow, we do property inspections before the work starts," he told reporters on Monday.
Dirt and rocks from the tunnelling will be used to rehabilitate sites such as a former quarry at Point Wilson and the former Orica site in Deer Park.
Premier Jacinta Allan said the project would support 12,000 construction jobs, take 15,000 trucks off local roads and save drivers 35 minutes when travelling from the east to the outer north.
"This is a project that has been talked about for decades and decades," she said.
"It's been the missing link in Melbourne's road network."
