A 16-year-old boy was flung off his moped when he collided with a van.
The youngster was travelling down London Road towards Hilsea, when he crashed into a white Renault Kangoo, which was turning right into Oakwood Road.
The rider, from Buckland, was taken to Queen Alexandra Hospital, Cosham, to be treated for serious leg injuries.
The incident took place just before 9am yesterday.
Alan Jackson, of Southampton, who works as a carpenter, was driving the van.
The 35-year-old said: ‘I’m shocked at what happened.
‘I was turning right and the moped just came down the bus lane.
‘I guess he was trying to beat the traffic and get to where he was going a bit quicker.’
Hampshire Constabulary is appealing for any witnesses to come forward and contact Police Sergeant Wayne Voller, of Fratton police station, on 101.