Motorists are being warned to expect road congestion and delays as music fans descend on Bramham Park for the 2003 Leeds Festival.
Blur will be headlining the last day of the festival
More than 50,000 people are expected to attend the three-day event, headlined by Metallica, Linkin Park and Blur.
The Highways Agency estimates that some 20,000 cars will arrive at the site near Wetherby between Thursday afternoon and Friday morning.
It is "strongly advising" motorists not attending the festival to avoid using the A1, A58 and A64 east of Leeds between Thursday afternoon and Sunday night.
The main entrances for those arriving at Bramham Park by car will be off the A64 York road.
Festival organiser Mean Fiddler is hoping fans will use a shuttle bus service between Leeds city centre and the site to avoid potential car queues.
Managing Director Melvin Benn said traffic arrangements had been planned in consultation with the police, Leeds City Council and the Highways Agency to "minimise disruption" for regular road users.
He said: "Contingency plans have been drawn up in the event of queues developing.
"The police will monitor traffic congestion on the local road network and, if necessary, put traffic control measures in place."