Motorists are being reminded by Highways England to plan their journeys ahead of the start of the annual three-day Devon County Show at the Westpoint Showground, Clyst St Mary, near Exeter.
The show, which runs from tomorrow (Thursday, 19 May) to Saturday, averages an attendance of up to 100,000 people over the three days, with increased traffic on the M5 north and south of junctions 29 and 30, the A30 east and west of Exeter and the A38 south of Exeter.
Traffic is likely to be heavier on the Saturday this year, with Exeter Chiefs hosting Wasps in an Aviva Premiership play-off semi-final at Sandy Park.
And Gareth Price, Highways England emergency planning officer for the south west, said:
Our aim is to keep the Highways England network running whilst keeping road users safe and informed.
Exeter Chiefs have published their own information to direct supporters on the Saturday, and we advise all road users to check our traffic and travel information channels, set off early and allow plenty of time.
Highways England provides live traffic information via its website or from a phone or mobile device at m.highways.gov.uk.
Travel information is also available by phone from the Highways England Customer Contact Centre on 0300 123 5000 and updates will be provided via Twitter.
Members of the public should contact the Highways England customer contact centre on 0300 123 5000.
Journalists should contact the Highways England press office on 0844 693 1448 and use the menu to speak to the most appropriate press officer.