A man in his fifties died in a crash on the A23 just north of Brighton this morning.
A 56-year-old van driver from Crawley has been arrested on suspicion of causing death by dangerous driving.
The van driver was heading south and appears to have lost control, crashing into the central reservation and knocking a lamppost over.
The lamppost hit another van travelling north on the other side of the road, killing the driver, who is believed to come from Eastbourne.
The accident happened at Pyecombe at about 5.55am and caused huge tailbacks in both direction during the morning rush hour.
The tailbacks also affected drivers on the A27 Brighton bypass.
At 11.30am Sussex Police said that the northbound carriageway remained closed and that one lane of the southbound carriageway had been opened.
Anyone who saw the accident or either van immediately before the accident is asked to contact Sussex Police on 0845 6070999.
