A driver has been taken to hospital and delays of up to half an hour are being experienced following a crash on the A27.
Emergency services are currently attending the eastbound collision at the Lyons Farm Retail Park on the A27 Sompting bypass in Worthing.
Police said a black Peugeot and a lorry collided at about 11.35am.
The driver of the Peugeot has been taken to hospital and officers said the extent of his injuries are unknown at the stage.
The crash has blocked the road between the junctions of the A280 and the B2222 Lyons Way - close to the Lyons Farm Traffic Lights - causing severe disruption between Clapham and Shoreham.