A specialised load transporter carrying an Airbus A321 aircraft fuselage, will be escorted by Wiltshire Police through part of the county on Sunday afternoon and delays to traffic are expected.
The journey will begin in Wiltshire at about 1pm from M4 Junction 18, depending on the weather, where the load will be transported in convoy.
It departs from M4 junction 18 to junction 15 before travelling north on the A419 towards Cirencester, then onto the A429 to arrive at Kemble.
The transporter and its load will measure 6.10 metres (20ft) wide, 4.93 m (16ft-01ins) high with an overall length of 46.00 m (151 ft) and gross weight of 58 tonnes.
While on the A419 it will take up both northbound carriageways and motorists are being aske to be patient and to allow extra time for important journeys.
The load is due to travel from MoD St Athan, near Barry, South Wales, to Cotswold Airport, Kemble, near Cirencester, Gloucestershire.
Regular updates and travel information in respect of this abnormal load will be passed from the Wiltshire Police control room at Devizes to help motorists plan their journey.
The police escort is being provided by volunteer officers on rest days, paid for by the haulier at no cost to the public.