Traffic queuing for an agricultural show in Nottinghamshire has caused severe disruption on a number of major roads around the area.
The event is being held at the Newark Showground in Winthorpe.
Police said queuing traffic on the A1 and A17 was causing tailbacks of up to seven miles (11 km).
The show is being held by the Lincolnshire Agricultural Machinery Manufacturers Association (LAMMA) until Thursday.
Motorists are being asked to avoid the area if possible.
A spokesman for Nottinghamshire Police said diversions had been put in place to ease the situation.