Goff is also supporting a proposal to fully integrate ferries into the public transport system. This will mean passengers are charged a fixed price for travel within certain zones, no matter what mode of public transport they use.
Currently, the ferry companies set their fares prices separately from the rest of the city's transport system.
The mayor says this will lower the cost of travel for about 28 per cent of ferry passengers who use a HOP card to catch a bus or train at either end of a ferry journey.
AT estimates it will lead to an estimated increase of 180,000 trips per year.
Both proposals have been promoted by the council's planning committee chair, Councillor Chris Darby, who represents Takapuna and Devonport. He said yesterday, "The poor cousin status of ferry users is no more with confirmation of integration of ferry-feeder bus and train fares with ferry fares."
Goff will be putting both proposals to the council next week in a "mayor's statement" about the annual budget. He said AT has estimated the two policies will have the "very low cost" of about $1.1 million a year.
The draft of that budget has already been through public consultation, without containing either proposal. That draft is now being amended and will come back to council for approval before coming into effect on July 1.
Neither the mayor nor AT has previously supported a policy of free fares, for anyone. It has arisen now as a result of a request to AT from the council's planning committee, to take a fresh look at ways to increase public transport use.
Darby said they had been consulting with AT on this since February. The free weekends proposal, he said, is part of a much larger raft of options under consideration.
The committee's deputy chair, Councillor Richard Hills, called it "step one".
"This is great first step in our desire to make public transport more affordable and easier for everyone with this first focus being on young people and families," he said.
"We hope to have free fares for under 15s in place later this year," Hills added. "I encourage all parents and caregivers out there to get their child a HOP card, leave the car at home and give public transport a go."
Goff was asked why he wasn't announcing a policy that would apply to weekday travel by children - wouldn't that have a much bigger impact on congestion?
"There are capacity issues," he said, "and also quite big costs to add at such short notice".
Did he support a policy of free fares for children on all days? He declined to say.
Darby told the Herald the first priority was children, and then they would be looking at easing the fare burden for students and other young people. The needs of community service card holders would also be considered.
Goff said he hoped all councillors would vote for the proposals he was announcing.