Two abnormal loads weighing a total of 190 tonnes will be trucked from the M4 on to the A419 tomorrow morning - 10 July.
Swindon police are warning of possible delays on those roads and others around Swindon.
The loads are panel presses weighing 110 and 80 tonnes, bound for the BMW plant in Swindon Road. Each is 4.9m (about 16 feet) wide.
The convoy, with private and police escort vehicles, is due to enter Wiltshire via Junction 18 of the M4 at about 11.30am, exiting via junction 15 and onto the A419 before travelling northbound towards Rat Trap.
The loads will exit at Rat Trap and travel along Highworth Road, Hobley Drive and then Swindon Road before arriving at their final destination.
The police warn that due to both width and weight, the loads will be slow moving and have the potential to cause congestion at junctions - and also within Swindon where oncoming traffic will be required to pull in and wait for the convoy to pass.
Wherever possible, disruption will be kept to a minimum although both hauliers and motorists are asked to be patient should they come across the convoy.
Anyone travelling over this period on time critical matters should allow sufficient additional time for their journey.
The police escort is being paid for by the haulier at no cost to the public.