The Forage is a showcase of street food by local businesses and food trucks. It was held at a new location at Dairy Road, Fyshwick, and was being promoted as the biggest event yet.

But by 6pm on Saturday, the event's Facebook page was awash with complaints from festival-goers urging organisers to call the police to help clear the traffic jam.

One person who spoke to The Canberra Times said after 70 minutes of being unable to get out of the carpark, they had called the police assistance line to request their attendance.

One woman posted on Facebook that "despite the delicious food and fun atmosphere, the day was ruined by the driving situation".

She said they were stuck in the "slowest moving line to get out".

"PLEASE LET US OUT", she posted.

Another woman posted that her family would never return to the event.

"We were stuck in the car in the sun with two crying screaming young kids for over one hour trying to get out of there," she posted.

"Our weekend was completely ruined."

Another Facebook poster said they had been waiting in the car park for 65 minutes.

"This is a safety hazard there's no way an ambulance or police car could ever get in or out."

"Absolutely bloody awful and shame on you for wasting the Saturday of hardworking Canberrans. Hire proper traffic management," the post read.

An organiser of The Forage said the issue arose from a large number of people attempting to leave the area at the same time creating a bottleneck in traffic.

He said the team were working with traffic management staff to do their best to relieve stress on the amount of traffic that had built up.

An ACT Policing spokesman said that no officers were on scene at 6pm and at that stage no police intervention was expected as a traffic management company was directing traffic.

The Forage was previously held at Little National in Barton but had changed location to Fyshwick which had allowed it to become bigger.