The festival, widely regarded as one of the best anywhere in the world, is set to be bigger than ever this year with up to 85,000 fans visiting the sprawling site each day.

Shops in Perth reported brisk trade, with camping equipment and beer the top sellers.

Kings of Leon are headlining today, while Franz Ferdinand, James Morrison and Idlewild also play. Tomorrow, The Killers headline and Snow Patrol and Blur will round off the event on Sunday evening. The weekend line-up also includes Lily Allen, Keane, Paolo Nutini and the Pet Shop Boys.

Also performing tonight will be Dundee favourites The View.

Around 4000 staff will be on hand throughout the festival, from cleaners and chefs to doctors and detectives.

And a staggering 126,473 toilet rolls are set to be used in the site’s 1192 portaloos.

While traffic was building up around Kinross today, delays were confined to the minor routes around Balado.

“There has been a steady build-up since first thing this morning and while there have been delays, they have not been significant,” a police spokesman said.

He said some snarl-ups would be inevitable and advised drivers to stay patient and follow the signs.

The Traffic Scotland website gives “real-time” traffic information for people still to head for T in the Park.

It also gives access to “live-eye” cameras which show traffic flow along the major routes heading to Kinross.

With tens of thousand headingto the festival, Traffic Scotland say anyone going by car should plan ahead and allow plenty of time for the journey.

Festival-goers travelling from the Highlands on the A9 have been warned that roadworks at Bankfoot will add to delays.

“We recognise that the A9 is the key artery to the Highlands for motorists and are keen that those visiting T in the Park have a great time and catch all the entertainment,” said a Traffic Scotland spokesman.