Queues formed on roads around Oxford today as thousands headed for the CLA Game Fair at Blenheim Palace.
This afternoon, traffic was reported as heavy around the city and at a standstill in places.
Drivers travelling from Witney towards Woodstock on the A4095 faced two-hour delays with queues starting at North Leigh earlier today, but at 2pm the traffic was reported to be easing.
Earlier delays on the A34 southbound from the M40 to Oxford were also reported as easing.
A broken-down motorhome at the Botley Interchange closed one lane of the northbound A34 and led to queues this afternoon.
And traffic is reported as heavy on the A34 from Botley to the M40.
Other delays were on the A420 approaching Oxford and the A40 between the Headington roundabout and the Wolvercote roundabout.
Slow-moving traffic was also reported on the B4044 between Botley and Eynsham in both directions.
Traffic is reported to have eased on the B4027 at Islip and the A415 Marcham Road, Abingdon.
At 11am, police said an accident involving an overturned vehicle on the A34 north of Oxford had been cleared.
Traffic has been at a standstill on the A44 approaching Woodstock, and the accident on the A34 northbound just after the Peartree interchange added to the congestion.
One car overturned at about 8.30am.
Claire Gourlay, a spokesman for Oxford Police, said: "The driver was fine and did not need any treatment from paramedics.
"The vehicle was recovered shortly after 10am and the northbound carriageway is now open."
Royalty and celebrities are joining the expected 138,000 visitors descending on the palace for the 50th anniversary Game Fair.
The event, which continues over the weekend, is the world's biggest sports exhibition and the national event for 50,000 owners of rural properties represented by the Country Land and Business Association.
Tomorrow, the Duke of Edinburgh will be popping in to tour the show and also present long service awards to gamekeepers.
Among the many celebrities expected to attend are Elaine Page and Bernard Cribbins, who have set their sights on raising money for The Children's Trust in a charity clay pigeon shoot.
The organisers of the Game Fair expect 138,000 people to attend the event, which started today and finishes on Sunday evening.
A car and a motorcycle were involved in a crash on the A34 Southern Bypass Road, blocking one lane early this afternoon.
The A424 Burford to Stow road was closed today due to a two-car crash at Merrymouth Road, Fifield.
Click here for latest news on traffic in and around Oxford.
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