The A27 between Lewes and Polegate will be subject to a rolling road block on Saturday (September 6) between 8pm and midnight as a large yacht travels through.
Motorists are being warned of the possibility of delays as a wide vehicle maked its way across the county.
Officers from the roads policing unit and the Highways Agency will be escorting a 6.7 metre wide yacht between Southampton and Polegate.
The yacht is being moved during the evening, being met by officers on the M23 at 7pm.
On the A27 between Lewes and Polegate between 8pm and midnight there will be a rolling road block because of its size.