The first race is set to start at 5.45pm.
Slider’s Lane near Uckfield is blocked both ways due to an accident between Ketches Lane and the A275 Lewes Road.
Slow traffic has been seen on the A27 at the Southerham Roundabout and on the A26 at Earwig Corner.
Delays have been seen approaching the roadworks in Polegate by the A27.
There are also temporary traffic lights due to roadworks on the A2100 at Telham and the A272 at North Chailey.
There is congestion on the A27 both east and westbound between junctions A286 and A259 Chichester East.
Delays of around 10 minutes are currently being seen.
Slow moving traffic has also been seen westbound on the A27 between A285 Chichester and the junction with A259 Chichester East.
There were delays on the A22 southbound by Holme’s Hill.
Delays were also seen on the Shoreham Bypass westbound towards North Lancing and by Mile Oak.
There was also congestion on the A21 southbound towards Baldslow.