The A272 has been blocked at Bolney after a three vehicle road traffic collision, according to Sussex Police.
Police said they were called to the incident just off the junction with Cowfold Road at 4.15pm.
Traffic reports suggest the incident is affecting traffic both ways between Pickwell Lane and the A23 (Bolney Cross).
A police spokesman said there were no reports of any injuries.
The collision is blocking the road and police are still on the scene.
Reports say traffic has not been helped by a closure to Cuckfield Lane which is causing traffic to divert on to the A272.