Woolworths/Caltex have had to redeploy petrol station managers from Hume and Gungahlin to deal with congested traffic at Majura Park described by one worker as a "shit fight".
The sight of parking attendants along Majura Road is the latest sign of Canberra's petrol wars, with Costco lowering prices to 98.7 cents per litre on Friday morning.
Staff at the nearby Woolworths-operated Caltex petrol station were watching the discounts across the road and offered fuel at 103.7 cents per litre, or 99.7 cents with a discount voucher.
"We're basically giving it away and keeping a close eye on Costco," said one worker as he marshalled cars to bowsers.
The staff member said the traffic was a "shit fight" throughout the day, and police had visited the store on Thursday to make sure traffic was moving safely.
The roundabout on Majura Road was occasionally being blocked by traffic around noon on Friday, and petrol station staff could be seen shouting instructions and waving signals to drivers.
Over at Costco, motorists said they had travelled from as far as Harrison, Belconnen and Tuggeranong to make the most of discounted fuel.
One motorist making the most of cheap fuel was Mary Colls from Belconnen, who said she brought snacks to occupy herself while waiting for petrol.
"I didn't even check the prices out there this morning because I know Costco is going to be the cheapest, so I just made the trek out here," she said.
"I love that there is competition in Canberra now and I've seen a few of the stations around here drop their prices as a result of Costco."
There were no lines for petrol at the Caltex petrol station at nearby Canberra Airport, but fuel was around 23 cents per litre more expensive than the Majura Park stations.
"The delays don't bother me as I just take a snack in the car. I know I'm going to have to wait but the wait is worth it," Ms Colls said.
"I'm saving about $30 a tank, easily and we fill both our cars up here."
Ms Colls wasn't the only one travelling across the ACT to Majura Park for cheap fuel, leading to traffic problems in the area.
Glenn Davies from Harrison said it was the cheapest he had seen diesel petrol in nearly 10 years, and was happy to come out of his way when he had time.
Alister Melhuish said he regularly travelled from Tuggeranong to Queanbeyan but was happy to detour out of his way due to the lack of cheap alternatives.
Many motorists at the Majura Park Caltex said they had made detours for cheap fuel but were not yet members at Costco.
The success of Costco has delighted NRMA ACT director Alan Evans who has called for more independent retailers to be opened across the territory.
"The line of cars queuing at Majura Park shows the impact that independent sellers can have in the ACT. Just imagine if we had more in the north, west and south of Canberra," he said.