Two cars caused rush-hour tailbacks when they had an accident on the A27.
The prang near the A23 London Road junction in Patcham, involving two Land Rover Discoveries, sent one hitting the central reservation.
Emergency services were called at 5.35pm today.
Police reported damage only with no injuries sustained.
A Sussex Police spokesman said the crash caused "carnage" because of the time of day at which the accident happened.
The road was reopened at 6.30pm with police directing traffic on its way.