A person trapped in the vehicle was rescued by the fire service following a crash on the A23.
The collision was on the road southbound between Bolney and Hickstead, West Sussex Fire and Rescue said.
A spokesman confirmed the service was called at 10.54am to reports of a vehicle on its side.
He added: “Crews from Crawley, Burgess Hill and Haywards Heath attended and helped one person from the vehicle.”
But the spokesman urged drivers to take care on the roads.
He said: “We have dealt with a number of road traffic collisions across West Sussex this morning.
“Please take care out there today, heavy rain showers are leading to a lot of spray on the roads.
“Always drive to the conditions, and most importantly #DriveToArrive.”