A milk tanker driver was taken to hospital after his lorry left the A272 Cowfold Road at Bolney in the early hours of Tuesday morning (Tuesday May 7).
Emergency services were called to the scene at 1.35am where the tanker, believed to be carrying around 22,000 litres of milk, had tipped on to its side.
The driver was taken to the Royal Sussex County Hospital at Brighton with serious injuries, which are not thought to be life-threatening.
The road remains closed in both directions between Bolney Cross in Bolney and Village Hall roundabout in Cowfold as rescue and recovery work to take place.
Another tanker had to be called in to transfer the milk.
Anyone who witnessed the collision or who saw the tanker in the area beforehand is asked to call Sussex Police on 101 quoting serial 58 of 07/05.