Congestion is causing problems on the A269 after an accident involving a car and a lorry partially blocked the road.
The accident happened near the junction with the A271.
A Sussex Police spokesman said: "At 6.08am on Thursday, 8 May police were called to a road traffic collision which had occurred near the junction of the A269 and A271 at Hazards Green, near Ninfield.
"A Ford Fiesta and a 7.5 tonne lorry had collided, but both drivers got out of their vehicles. One man was taken to the Conquest Hospital, St Leonards-on-Sea, by ambulance after complaining of chest pains.
"Anyone who saw what happened is asked to phone Sussex Police on 101 or email email@example.com quoting serial 152 of 8/5."