The member for Maiwar has called on the Queensland government to consider a Greens proposal to introduce free public transport for all children aged under 18.

"Free public transport for every kid in Queensland, from Brisbane to Cairns, would cost just $56 million per year," he said.

"Just for context, the government will spend $2.5 billion just this year on roads."

Mr Berkman said the plan would mean "no mucking around with Go Cards" and less hassle for parents.

"For kids in my electorate, in the outer suburbs, and especially in families that don't own a car, it would mean a new sense of freedom," he said.

"For people who have to drive, this would also mean getting cars off the roads at drop-off times, which would do wonders to ease congestion."

Mr Berkman said it was important to get children out of cars, which meant making walking, cycling and catching public transport to school easy and safe.

"Alongside infrastructure for cars, there are plenty of practical steps we could take to ease the school drop-off crunch, including longer pedestrian crossing times, permanent 40km/h speed zones and better funding for the active school travel program," he said.

Transport Minister Mark Bailey said the government already subsidised public transport across south-east Queensland by more than $1.9 billion a year.

"The revenue we collect from fares forms about 20 per cent of the cost of providing services," he said.

"Offering free travel would further reduce the revenue that could be reinvested in new and improved public transport services for everyone, like Cross River Rail and the Sunshine Coast rail duplication."

Mr Bailey said the Fairer Fares scheme introduced in 2016 had saved Queenslanders $138 million so far.

The Queensland Greens policy also includes $1 flat fares, three new green bridges in Brisbane, more separated bike lanes and a minister for public transport.

Concession fares are 50 per cent cheaper than adult tickets. A one zone on-peak concession go card trip costs $1.66 in south-east Queensland.

Travel on the TransLink network is free for children aged four years and under.

Children aged between five and 14 travel free on the weekend when they use an orange child Go Card.