The A27 will be completely closed in both directions at Fontwell to allow a crashed concrete truck to be recovered, police confirmed.
Both east and westbound carriageways between Fontwell and Tangmere will be shut between 2pm and 3pm, with the vehicle currently on its side after it overturned onto the central reservation early this morning.
The Mercedes-Benz vehicle, configured as a concrete pump, crashed at around 6.40am (Friday, February 9), while travelling east between Chichester and Arundel, damaging the crash barrier.
Police said the driver and a passenger sustained minor injuries and no other vehicle is believed to have been involved.
The road was partially blocked from the outset, causing heavy morning rush-hour delays.