A lorry and four cars crashed on the A23 by the slip road for the A27 Brighton Bypass during the rush hour this morning (Thursday 7 November).
All five vehicles were travelling south by the Patcham junction when the lorry clipped the kerb.
Sussex Police said: “Four other vehicles which had minor bumps while braking.
“One man received minor injuries and was treated at the scene.”
Traffic officers are appealing for witnesses to contact them after a car hit emergency barriers on the A27 Brighton Bypass in a separate incident this morning.
The driver of a grey Rover 600 lost control of his car and was left facing the wrong direction as he was heading west towards the Southwick Tunnel at about 7am.
He hit the central reservation and his car span around. It stopped parked in a hatched area close to the tunnel entrance facing eastbound.
Officers turned the car around and moved it to a layby on the west side of the tunnel. It suffered minor damage and the driver was unhurt.
PC Wayne Dixon said: “I’m keen to speak to anyone who was in the area at the time and saw the Rover hit the central reservation.
“I’d also like to speak to anyone who may have seen it being driven in the minutes before the crash.”
Anyone with information is asked to call Sussex Police on 101 or email collision.appeal@sussex.pnn.police.uk.