A 21-year-old motorcyclist is in hospital in Southampton with serious injuries after a collision on the A259 Via Ravenna in Chichester on Sunday morning.
The incident happened at around 11am. The biker, from Chichester, was riding an orange and black Suzuki motorbike which left the road and collided with a lamp post.
Sussex Police are asking anyone with information about what happened is being asked to contact Sussex Police on 101 quoting Operation Duffield.
"The road was closed until 4.45pm while police carried out an investigation. This caused a lot of traffic disruption in the area and we would like to thank the public for their patience and understanding."