One lane of the A27 remains closed between Shoreham and Lancing after heavy flooding yesterday (December 23).
Tailbacks from the Sussex Pad traffic lights stretched more than three miles yesterday after Highways England closed one carriageway, declaring a 'critical' incident.
Congestion continued throughout the day following the initial closure at around 8am.
Traffic spilled out into surrounding roads as motorists tried to find alternative routes east.
A wet December has caused flooding chaos around the area, with many residents in Lancing left unable to flush their toilets due to overflowing sewers.