Families are cancelling or scaling back their Easter trips despite fuel prices already starting to fall as an excise cut kicks in.
The federal government has temporarily halved the fuel tax, shaving 26.3c per litre off wholesale prices in a bid to head off the worst economic effects of war in the Middle East.
The NSW government's FuelCheck website showed average prices for E10 unleaded petrol had dropped more than 14c on Wednesday, the first day of the excise cut.
Diesel prices were down a more modest 6c as many service stations experienced shortages.
Regional service stations were unlikely to introduce lower prices for a couple of weeks as they needed to sell their older, higher-taxed stock before bringing in cheaper fuel, NRMA spokesman Peter Khoury told AAP.
That process would likely take anything from a day or two for high-turnover metro stations to two or more weeks for some regional sites, he said.
"Once they buy new fuel, they will pass the discount on at that point."
Data from the Tourism and Transport Forum compiled in late March found 41 per cent of Australians had already cancelled or scaled back their Easter travel plans during the fuel crisis.
"Measures like the fuel excise cut are designed to ease pressure and we'll see over the coming days how much that shifts behaviour," forum chief executive Margy Osmond said.
"What we do know is that most Australians aren't giving up on holidays. They're adapting to make them work."
The consumer watchdog would be checking to ensure service stations passed on the price cuts to consumers, Treasurer Jim Chalmers said.
But he reiterated the change would not kick in straight away.
The Northern Territory government has triggered a 77-year-old law to force fuel retailers to front up with their cost structures to prove they aren't ripping off consumers.
It was the first time the Price Exploitation Prevention Act had been enacted since its inception in 1949, NT Treasurer Bill Yan said.Â
"Under the Act, we can request an open-ended amount of data from retailers, prohibit transactions and, if there is evidence of price exploitation, we can intervene," he said.
Former Australian Competition and Consumer Commission boss Allan Fels said there was no law against price-gouging, but public shaming would be a powerful tool to force fuel companies to do the right thing.
"The ACCC has no direct powers either to set maximum prices or to fine companies for excessive pricing or price-gouging," he said.
"But the ACCC can publicly criticise someone that's not passing on the benefit."
The watchdog would also need to keep a close eye on the "rocket and feather" effect on fuel prices, Professor Fels said.
"When costs go up, prices go up like a rocket. When costs go down, prices fall slowly like a feather to the ground," he said.
States and territories are considering further changes that would see them forgo some of their GST revenue on higher fuel prices, but have been unable to agree on the best mechanism to pass the savings on to consumers.
Some states want to reduce the 10 per cent GST on petrol and diesel, giving motorists a direct benefit, while others are keen to keep the rate as is but use the increased revenue to fund broader cost-of-living aid.