Public transport services would arrive every 10 minutes across Queensland and be free in two years under a Greens election proposal.
But a transport union says it is a costly fantasy to roll out the services needed to meet the commitment.
The Greens would expand the public transport network to have buses arrive every 10 minutes in the south east and 25 regional areas including Townsville, Cairns and Toowoomba.
The rail network would also be boosted to have trains arrive every 15 minutes or faster in the southeast.
"What we can't afford to see is countless Queenslanders not able to make the most of 50-cent fares because the services in their area are so poor," Greens MP Michael Berkman told reporters.
Greens MP Michael Berkman says public transport should be free. (Darren England/AAP PHOTOS)
The Greens also committed to keeping the 50-cent fare scheme which both Labor and the Liberal-National Party have promised will stay if either are elected in October.
But the party wants to make public transport free by 2026, costing $390 million in foregone revenue a year.
"Public transport is a public service. It should be free," Mr Berkman said.
Rail, Tram and Bus Union Queensland Secretary Peter Allen said 50-cent fares have revolutionised public transport usage in the state.
In just over a month south east Queensland usage rates for buses have risen by 16 per cent, ferries by 43 per cent and trains by 22 per cent compared to 2023.
In the regions, Mackay recorded 30 per cent more people using public transport, Whitsundays was up by 21 per cent and Bundaberg was up by 11 per cent.
"Customer complaints have gone right down, the number of incidents have gone down, customer satisfaction is through the roof," Mr Allen told AAP.
"So these are all really good things that sit on top of these record increases in patronage."
But Mr Allen said the Greens proposal for more frequent public transport across Queensland is an expensive pipe dream.
"It sounds great, but it's a fantasy," he said.
"There just isn't the infrastructure to support that."
Mr Allen said it would be fantastic if services could be ramped up quickly but it takes years and significant investment, far more than the Greens' $14.7 billion proposal.
"It's just outside the bounds of what's available," he said.
As for free fares, Mr Allen said without the data of people tapping on and off, transport wouldn't know where the demand is or where services are required.
"Having a nominal fee makes a difference that way," he said.
Mr Allen said studies overseas have shown free public transport increases the disrespect of the services with people "trashing" trains and buses.