The A24 is currently closed due to a two-car collision south of Washington in which four people have been injured.
Two cars were involved in the accident, which happened near the Washington roundabout this afternoon.
Sussex Police were called to the scene by the ambulance service at just before 4.20pm to make the scene safe.
Four people were injured in the collision: three with whiplash, and one with more serious injuries who may have to go to hospital, according to a police spokesman.
Police closed the A24 between The Pike and Washington Bostal this afternoon so debris can be cleared.
The accident is currently affecting traffic from Washington and Findon, and the road remains closed at the time of publishing.