Fieldays posted on its Facebook page explaining the traffic situation, urging motorists to "bear with us" as traffic management and police dealt with the congestion.
However, Fieldays attendees have taken out their frustration on the post, reporting huge waits without moving on the darkening fairgrounds.
"Absolute bull**** Fieldays! The accident wasn't in the Carpark. We are in the orange Carpark, haven't moved in 2 and a half hours. We have a tired 3 year old, and a 6 month old in the car. With no food or water! I know we are not the only ones. There is no traffic management! That's a pack of lies! Absolutely disgraceful!," one motorist posted.
"Absolute disgrace , orange carpark traffic had not moved for 2 hours while traffic to the left is moving, no traffic management in place just appalling," another commented.
"Fieldays what about providing refreshments for the people you've trapped in orange for two hours or at least toilets? Human decency would be appreciated," said another.
"Appalling courtesy by some drivers by not letting people merge," another post said.
However, one motorists contacted the Herald to say the issue was not the 4pm crash on SH1 but simply Fieldays had crammed too many vehicles into a single carpark.
"An Absolute Joke! Have just got out after a 2 1/2 traffic nightmare . The accident was not the issue. They have crammed to many vehicles into one car park with only one exit," Alex Anderson said.
"There were many thousands of cars in the orange car park with only one exit on to Airport Rd.
"They really need to take a serious look at this and spend some money. The police used to direct traffic! There was only one guy on the road and some random dude in the carpark doing it."
At 7pm, Fieldays posted on Facebook that the "earlier traffic incident which has caused delays has now been cleared and traffic is now moving freely".
However, many motorists replied to the post, dismissing Fieldays assessment, also suggesting the traffic jam was due to poor organisation.
"hmmmm... no incident in car park .. just poor organisation/ management.... finally directed across paddock to another exit and heading in opposite direction to where we need to go," one person wrote.
"Fieldays the problem wasn't the accident. You need better traffic management in orange car park. Hope you do better tomorrow. At least we won't be there !!," another person said.
As of 6.15pm tonight some motorists were reporting movement out of the Fieldays carpark.
However, NZTA still had an Area Warning for SH21 Mystery Creek Rd in place as of 8:15pm tonight.