Tram travel in Melbourne's CBD will be free from midnight on New Year's Day.
The policy was announced under the former coalition government but officially launched by Labor Premier Daniel Andrews.
He said the move would make it easier for tourists and visitors to get around the city.
"We've got the Asian football cup, we've got the Cricket World Cup, we've got the tennis and all the other school holiday activities," Mr Andrews told reporters on Wednesday.
"The opportunity for people to travel in that grid free of charge on iconic Melbourne trams, that's exactly what we need."
Opposition emergency services spokesman Brad Battin slammed Mr Andrews for taking credit for the free tram policy, which was funded in the 2014 state budget.
"We're calling on Daniel Andrews to make a New Year's resolution not to claim credit for free trams in the CBD," Mr Battin told reporters.
"It was a policy announced by the Liberal government and we want him to say that."
Public Transport Victoria chief executive Mark Wild said there was no need to touch on and touch off using the MyKi public transport cards in the city.
"If you do accidentally touch on in the free zone, we encourage you to touch off and you can claim that fare back," he said.
Mr Wild said people travelling from the CBD to another suburb on a tram would still need to touch on as usual.
The free tram zone includes the area from Queen Victoria Market, to Victoria Harbour in Docklands, up to Spring Street, and over to Flinders Street Station.
Mr Andrews said January 1 would also see the introduction of cheaper train travel between Melbourne's outer suburbs, another coalition policy announced earlier in 2014.
He said work was continuing on Labor's plan to introduce 24-hour public transport on weekends, with a year-long trial scheduled for 2016.
