Flooding is causing chaos for people heading to the Isle of Wight Festival.
Heavy rain has led to access problems at Seaclose Park, Newport. There has been traffic gridlock on the island with people forced to sleep in their cars overnight.
Police have been escorting motorists stuck in traffic to Newport Football Club where shelter and refreshments are being provided.
About 65,000 festival-goers are expected to attend the three-day event.
Traffic on many of the island's roads has been at a standstill throughout Thursday and into Friday.
Hundreds of motorists have been queuing for up to ten hours to access the site and have been left stranded in their vehicles.
Fiona Gregory, from Salehurst in East Sussex, said she had planned the trip for months with her three children and a friend.
They left home at 13:30 BST on Thursday, arrived on the island nine hours later after ferry delays at Portsmouth and were still waiting to access the site at 03:20 BST on Friday.
She said: "I'm so upset. It's a complete disaster.... On the island it has been a nightmare. There is no police, no diversion signs, nothing.
"Now we're about two miles away on a country lane and we have moved one mile in the last four hours."
Festival-goers have taken to social networking sites to complain about their treatment and a lack of communication from festival organisers.
Amy Neale wrote: "This is diabolical. I cannot believe that an organisation that is taking this much money per ticket actually think this is decent."
In a statement issued at 01:00 BST, festival organisers said: "We are really sorry for the delays getting into the campsite.
"Our fields have become wetter and wetter throughout the day. We have opened up new fields and laid more trackway.
"If you are in a car outside waiting to get in we are sending you some food and drink. Please bear with us."
Hampshire Constabulary said it was escorting motorists on the A3054 main road from Fishbourne to the car park at Newport Football Club.
The force said traffic on the A3021 road from East Cowes was being marshalled into the existing festival car parks.
Plans are being made to open extra car parks for people due to arrive on the island later on Friday.
Earlier, three Wightlink ferries with a total of 600 people on board were forced to wait in the Solent for several hours.
The ferry firm said it had been unable to unload cars in Fishbourne because of traffic being stacked up to the sea.
Food on board
Problems began in the morning because the main car park had become waterlogged from heavy rain overnight.
Organisers were forced to bring in metal tracks so that vehicles could be directed to an overflow car park.
Thousands of people were also stuck in Portsmouth harbour waiting to board Wightlink ferries to the island.
The organisers apologised and said they were "working to speed things up" at the parking site.
John Newsome, who had been stuck in the queue for several hours, said: "I'm quite happy with the festival.
"Really up until this year, the traffic situation has not been too bad - fair enough, it's been a bit disruptive but not too bad.
"But this today, it's disgusting. I've never come across anything like this in the past here - or even on the mainland.
"It makes everyone's blood boil and this will make people even more irate and cause accidents."
Southern Vectis said its bus services were affected.
At the festival site one of the stages, Big Top, was closed for a short while on Thursday because of high winds but reopened later.
Warm-up acts were playing ahead of the official start on Friday.
The festival runs from Friday until Sunday and headliners include Tom Petty and the Heartbreakers, Pearl Jam and Bruce Springsteen.
The date of the event was moved from its normal slot in early June, to avoid clashing with the Diamond Jubilee and half-term holidays.
For the festival about 65,000 people travel to the Isle of Wight, which has a population of just 140,000.