Canberra is Australia's third-most expensive capital city for petrol

But before he headed home on Wednesday, he took a seven-minute detour to Fyshwick to fill up his car.

Mr Anderson is among the Canberrans who form long queues at Metro Petroleum Fyshwick, believing it to have the city's cheapest fuel.

"I drive past about five servos before I even reach this one," Mr Anderson said.

"I come here all the time because their prices are always low and nothing really compares to it."

The Australian Competition and Consumer Commission's latest petrol monitoring report found Canberra was the third-most expensive capital city for petrol, behind Hobart and Darwin.

The average price in the ACT in June was $1.55 a litre, a 9-cent increase from March. Hobart was the most expensive at $1.59 a litre, followed by Darwin at $1.56 a litre.

In the year to June 2018, monthly average retail prices in Darwin, Hobart and Canberra were higher than the five-largest cities including Sydney and Melbourne.

Petrol prices rose almost 10 per cent to a four-year high across Australia's five major cities last financial year, with the average price at the bowser hitting $1.35 a litre.

The report said the average annual petrol price had jumped from an average $1.22 a litre in 2016-17.

For Canberrans and people in surrounding regions, searching for cheap fuel is limited to a few locations.

On Wednesday afternoon, the cheapest petrol people could buy was $1.39 a litre at Costco at Majura Park. The Metro at Fyshwick came in second at $1.40.

In the city, BP and Caltex in Braddon were selling at $1.50 a litre and neighbouring Coles was $1.54. The average in Canberra was about $1.50.

Mr Anderson was unsurprised Canberra had the nation's third-highest prices.

"We have higher incomes, so I guess they think people can afford it so they keep putting it up," he said.

Commission chairman Rod Sims said the OPEC oil cartel's slashing of production levels was one of the main reason for higher oil prices.

"The major factors driving higher prices were an increase in international crude oil and refined petrol prices, and a lower AUD-USD exchange rate," Mr Sims said.

"The OPEC cartel, in particular, continues to have a damaging effect on Australian petrol prices. In late-2016, OPEC and some other crude oil producing countries agreed to cut production. This restricted supply into the market, which has clearly started to bite through steadily increasing petrol prices in the past financial year."

Mr Sims said the weaker Australian dollar also contributed to higher costs for wholesalers buying fuel and they were passing these costs on to consumers. Petrol retailers increasing their gross margins were also contributing to price pressures.

Like Mr Anderson, Queanbeyan resident Christopher Hood is a frequent user of the Metro in Fyshwick.

"I don't make a special trip to this service station, but I pass it often enough that I can conveniently drop in and get petrol here," he said.

"It's worth it because petrol prices in Queanbeyan service stations are particularly high at the moment – 10 or 15 cents per litre difference."

Queanbeyan's average June price for petrol was slightly cheaper than Canberra's, at $1.54 a litre. In surrounding regions, Cooma's average was $1.56 a litre and Batemans Bay was $1.54.

For those who travel between Canberra and Sydney, Goulburn's average for June was $1.51.

Mr Sims said motorists could save on fuel by downloading fuel monitoring apps.

He said taking measures such as buying only small amounts of petrol when prices were at their peak and waiting until they fell before filling up would also save money.

The full report can be found here.

with Markus Mannheim & Cole Latimer