Some services will resume on Sydney's inner west light rail network as early as February, with all cracked trams to be repaired by October 2022.
Transport Minister Rob Stokes announced last month that all 12 trams on the city's inner west line would be decommissioned for up to 18 months to fix major cracks - up to 30cm long - on the rolling stock.
But on Thursday he revealed the light rail cars would be back up and running in less than a year.
In the meantime, services running every 15 minutes will progressively resume from as early as February, with trams borrowed from the CBD and southeast light rail lines.
Commuters will be able to catch the light rail from Lilyfield to Central, and Transport for NSW hopes the service will be extended to Dulwich Hill by mid-year.
"I'm hoping by the middle of next year we will be able to restore the full frequency of the full line to the inner west light rail," Transport for NSW chief operations officer Howard Collins told reporters.
"And in the meantime, we're obviously working very closely to ensure customers get around the city, but over 3000 people a day are using the three (replacement) bus services and several hundred are now using the (replacement) ferry service."
Testing of the borrowed trams, which have slightly different specifications, is under way.
"I'm pretty confident we're going to achieve this - 95 per cent absolutely sure that we're going to get there by February," Mr Collins said.
"We've just got to get those final things checked."
There may be a slight gap between the trams and platforms along the lines, but staff would be on hand to help people board and alight, Mr Collins said.
It remains unclear where the blame lies for the faults that halted the seven-year-old trams, Mr Collins said.
The cracking found during routine maintenance was probably a design flaw that would have global implications, Mr Stokes said when revealing the issue last month.
About 1000 similar trams are in use around the world, including in Newcastle and Canberra.
Mr Stokes on Thursday acknowledged the debacle had been "enormously frustrating" for commuters.
"It is a terrible situation," he said. "My sincere apologies ... go out to those commuters whose lives have been affected."
But NSW Shadow Minister for Transport Jo Haylen says commuters are owed more than an apology.
She says the government should still offer half-price fares for commuters travelling between Lilyfield and Central, in line with compensation for commuters forced on to replacement buses.
"Passengers shouldn't be paying full fare for a shuttle service that's less frequent and slower," she said.
