It got so bad at the roundabout last summer that the council was forced to introduce stop/go signs at pedestrian crossings.
He told the Bay of Plenty Times that the idea might not be the best for retailers but Mainstreet had to think of the frustration being experienced by holidaymakers.
Mr Melgren said Mainstreet would be guided by advice from council traffic engineers on what would work. For instance, the advice might be to trial the one-way system on the southern half of the shopping centre.
Councillor Leanne Brown argued the Labour Weekend trial should include the Friday and Tuesday on either side of the weekend so they were able to gauge what normal weekdays would be like. The trial would also test how closing the roundabout to northbound traffic would impact on bottlenecks normally associated with the weekend's popular Wheels on Mainstreet event.
Mr Melgren agreed with Mayor Stuart Crosby that it was not a new idea, but until they ran with it they would not know if it worked.
Retailers were about 50/50 in favour of the proposal.
He said the plan would never solve all of the Mount's peak parking and traffic flow problems, but common sense was needed to balance some of the challenges. Tauranga people who avoided the Mount at the height of the summer might even be lured back.
Menswear retailer Charlie Robertson backed an investigation even though he was wary about the potential for confusion and the extra pressure it could put on Prince Ave, which was already difficult for drivers because of its narrowness and angle parking.
"I would not want to see it all year round."
He saw merit in Maunganui Rd staying two-ways past the Prince Ave roundabout so people could enter the Phoenix Carpark from both directions. The future of the carpark will be decided on August 25.
Mainstreet chairwoman Jane Debenham said the board had considered the idea informally but it had not been to members. "It is something we are putting out there to see if it gets any traction. It may not be the right thing but until you ask the question you don't know."