The A24 is partially closed due to a car collision at Buck Barn, police said.
Sussex Police said: “Police were called after a car collided with trees on the A24 at Buck Barn, Southwater, at about 7.12am on Friday (16 June).
“The northbound carriageway is currently closed while the vehicle awaits recovery and the scene is made safe.
“No other vehicles were involved and no injuries have been reported.”
The incident is causing long delays between Worthing and Horsham.