Hampshire Police have arrested a 29-year-old man on suspicion of dangerous driving, driving with an unsecured load and causing danger to other roads users, following an accident on the A34.
It's understood that a car transporter which was being towed by a recovery vehicle on the northbound carriageway came free and crashed through the central reservation shedding its load in the process.
Hampshire Police say the transporter and vehicles have been cleared away but the road is likely to remain closed for several hours while repairs are done to the road surface.
Hampshire Police say that the A34 is likely to remain closed in both directions for most of the day as repairs are made to the road surface following a serious accident overnight.
It's understood that a transporter lorry hit the central reservation near Whitchurch in Hampshire, causing the cars it was carrying to fall onto both the north and south bound carriageways.
Police and Highways Agency staff have been at the scene since 11:10pm last night.
No one was hurt in the accident and no other vehicles are believed to have been involved.
Drivers hoping to use the A34 today are being advised to take alternative routes.