Brotherston said young people were waiting in a queue that stretched several kilometres from the festival site at Wainui Beach back to Raglan town in pouring rain.
Those driving to and from the event were becoming increasingly frustrated on the surrounding roads.
"This is a rural two lane road. There is no traffic management plan. People in the queue are getting frustrated, putting their hazard lights on and driving on the wrong side of the road towards people like me who have just dropped people off. It's just chaos."
"I just can't believe an organisation like this is able to put on a massive event, in the middle of nowhere, knowing most people are coming from Auckland, Hamilton, New Plymouth, or Taupō, and there is no traffic management."
Soundsplash organisers said they were working as fast as they could to get people safely into the festival.
A spokeswoman said they were experiencing the usual gate and traffic delays that happen with all festivals.
"We have tried to communicate clearly to our patrons about the expected delays when dealing with a town like Raglan which imposes challenges such as two one-way bridges, and narrow roads, however we know this beautiful site is worth it! Everyone inside is very positive," a spokeswoman said.
Ensuring security staff were carrying out searches of vehicles was still at the forefront for organisers, she said.
The situation was improving at 2pm and people were entering the event smoothly/
In a post on their Facebook page, they urged those waiting in cars not to drive on the wrong side of the road and to stay in their cars.
Organisers said they would hate for anyone to get hurt and were calling for people to be patient.