The Auckland Council is considering making public transport free for children under 15 on weekends and public holidays.
The proposal has been discussed informally by councillors and Auckland Transport, but would have to be approved by the full council as part of its budget process.
Mayor Phil Goff said he hoped it would encourage more children and families to get around the city on public transport and would help deal with congestion.
He said it could be expensive for whole families to take public transport.
"That means mum and dad are going to consider, 'hey maybe we'll hop on the bus and go to the museum, go to the zoo' do something else in the public realm."
Mr Goff said during the weekends there was normally a lot of space on buses and trains.
The plan could increase the number of public transport trips taken in the city by one million a year, he said.
Councillor Richard Hills said public transport could be really expensive for people with several children.
He had a lot of positive feedback from families after just one day of free public transport the Friday before Christmas, he said
"It really opens up Auckland for parents to take their kids as a family on the public transport system because at the moment it is probably cheaper for them to take the car," he said.
Mr Goff said he hoped the fares would introduce some people to public transport who might then continue to use it.
He would eventually like to see the policy widened to include weekdays but it was too expensive for now, especially as the council had just had to find $500 million extra for the City Rail link, he said.
If other councillors support the plan it would most likely be in place by the end of the year.
Children currently travel at a discounted rate on Auckland public transport, with under-5s already free.
If implemented, the move would be a first for a major New Zealand city.
Commuters in the city centre had varying opinions on the proposal.
Michael Sprague, a father of three children under 10, said it was a great idea.
"My wife and I often think that coming into the city on the weekends. We would like to take the kids on public transport, but it's cheaper to take a car when you've got a family of five," he said.
"The kids will enjoy it. They love riding on the bus."
Mr Sprague added that if they're taking public transport, they didn't have to worry about the expensive parking fee.
Auckland woman Raquel Macam, whose daughter is nearly 5, said the proposal was an incredible idea and hoped it will be put into practice.
"Every weekend having free transport that will be a great help to us parents. Especially over the weekends, that's family when you usually go out. Especially in my case that we don't have a car and we use public transport - bus, train - to go everywhere," she said.
International student Nana Chio, 14, takes the bus every day to school, was a little bit disappointed the free rides applied only on weekends and public holidays.
"I don't always go outside on weekends, so that's not very useful."
Another Aucklander, Deepti Chauhan, has a 7-year-old, but said her family was unlikely to take advantage of the free trips.
"We usually don't take public transport. We use our car. It's more convenient when you have kids around, so I don't know whether it make too much of difference."