The festival is headlined by Adele and Coldplay
Festival-goers heading off for Glastonbury risk being stuck in 11-hour traffic jams and are being urged “not to set off”.
The delays are being caused by wet weather but organisers said they are making solid efforts to “deal with this situation”.
Festival founder Michael Eavis said: “We did ask people to come in later.”
More than 100,000 people are expected to flock to Worthy Farm to attend the five-day event.
If you’re coming to the Festival by car or campervan and are yet to begin your journey, please do not set off yet. pic.twitter.com/0APeaMsyBO
— Glastonbury Festival (@GlastoFest) June 22, 2016