Thousands of people have flocked to Cheshire for the Creamfields festival.
The two-day dance music extravaganza, which celebrates its 10th anniversary this year, is being held at Daresbury near Warrington.
The star-studded line up includes Fat Boy Slim, Pete Tong, Kasabian and Beth Ditto's band Gossip.
About 40,000 revellers attended last year's event where 22 people were arrested for various offences such as drug possession and drink-driving.
However, Cheshire Police, which has about 800 officers on the site, said reported crime at the 2007 event had dropped by about 80% on the previous year.
Traffic management
Insp Debbie Dodd said: "We have had in-depth discussions with the organisers of the event, the two local authorities and the Highways Agency and produced a detailed traffic management plan.
"This addresses the fact that extra people will be travelling into the area, the likelihood of any congestion on local roads and what plans are in place if there is a major incident on any roads."
Drivers in the local area are being advised to allow extra time for their journeys and to be alert as the roads will be busier than normal.
A number of roads in the locality will be partially closed through to the end of Sunday, although residents will still be able to gain access to their homes.
Shuttle buses
Warrington Road will have partial closures at both ends, Daresbury Lane will be closed after the south car park and Delph Lane will also have partial closures.
There will be no left turn off the A49 at the Cat and Lion into Hatton Lane and Keckwick Lane will be closed completely.
There will also be a partial closure off the A56 Chester Road at the junction with Newton Lane. At this junction, drivers will be able to turn right into Newton Lane but will be unable to turn left towards Daresbury village.
Shuttle bus services are running throughout the weekend from Liverpool, Manchester, Warrington, Widnes and Runcorn.
