The A283 at Stopham Bridge west of Pulborough has reopened in both directions following an accident involving a motorbike and a car.
Sussex Police were called at 1.50pm today and the road was reported closed at 2.05pm, remaining that way until about 3.30pm.
The collision took place before the bridge by a nursery.
An ambulance was on the scene to treat serious injuries.
The road was closed both ways between Lea Farm Lane and the A29 London Road.