The AA said Golden Jubilee Way is closed southbound between Dittons Road and Willingdon Drove due to a stalled lorry.
The incident was first reported to the AA at 1.23pm today (Wednesday, May 25).
An eye-witness said there is an oil spill which could leave the road closed for ‘at least a few hours’.
Sussex Police said, “We are supporting Highways with the closure while the carriageway is cleared.”