The emergency services are facing a busy evening with multiple incidents reported across the county.
The most serious incident has been reported near Bognor Regis.
The A259 is closed westbound after a crash involving a motorbike and three cars between Stanhorn Grove and A29 Shripney Road.
Further delays have been reported around Middleton on Sea and Bognor Regis. Traffic is increasing on B2259 Flansham Lane eastbound between Upper Bognor Road and A259, as well as on A259 Worms Lane westbound between A259 and B2132 Yapton Road.
'Severe delays' are said to be gradually easing on Drayton roundabout Eastbound between A27 Chichester Bypass and the A259.
Delays remain on A259 Chichester Road southbound at Elbridge Avenue, with the 'usual delays' heading towards Bognor Regis.
Traffic is reportedly queueing on A27 both ways from A285 Portfield Way to A259 Cathedral Way (Fishbourne roundabout).
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Heading towards Horsham, there is traffic congestion on A272 both ways at A281. 'Usual delays' have been reported heading into Cowfold.
In Mid Sussex, one lane is blocked, with queueing traffic due to a stalled vehicle on A23 Southbound at B2118 Mill Lane (Hurstpierpoint / Sayers Common turn).
After fire crews rescued a person from a Southwater mud trap this afternoon, there are now reports of mud in the road at Aridngly in Cinder Hill Lane, around Horsted Keynes Industrial Estate. Traffic is said to be coping well but motorists are advised to approach with care.
In Arundel, there are 'severe delays' on Chichester Road eastbound between A27 Arundel Road and A27 The Causeway. There are also queues on A280 Southbound at A27 Arundel Road (Angmering / Clapham junction).
Towards Littlehampton, there are eastbound delays on the A259 between South Drive and A280 Angmering Bypass (Blue Star roundabout).
In Worthing, there is slow traffic on A27 both ways, with congestion to Findon Valley.
Traffic is queueing on High Street westbound in Lancing.
Delays have also been reported on A27 Old Shoreham Road westbound between A270 Upper Shoreham Road (Southwick / Holmbush turn off) and A2025 Grinstead Lane (Sompting Roundabout).
Queues are building on A27 both ways between A2038 King George Vi Avenue (Hove turn off) and A270 Upper Shoreham Road, in the construction area.
Two crashes have been reported in East Sussex.
Two cars have reportedly collided on the A27 at The Street in Selmeston. The road is partially blocked, affecting traffic travelling between Polegate and Lewes.
A motorbike has been involved in a collision at Maresfield. The A272 is blocked both ways from Lodge Lane to A22, with heavy traffic.
Elsewhere, delays are increasing on A27 eastbound towards The Village (Alciston turn-off)
However, delays are easing on A27 eastbound between A27 and A259 (Pevensey roundabout).
Delays of two minutes on A259 East Dean Road Westbound between A2270 Upperton Road and Upland Road. Average speed ten mph.
Delays are reportedly increasing on A27 westbound between A23 London Road and A293 (Portslade / West Hove turn-off).
'Severe delays' are said to be increasing on A27 eastbound between A283 Steyning Road (Steyning turn-off) and A2038 King George Vi Avenue (Hove turn off).
In Brighton, there is traffic congestion on A259 Kings Road around the i360 and the pier.
Delays are building on B2123 Falmer Road southbound, with congestion on Warren Road.
The average speed is reportedly just 15 mph on A27 eastbound in East Sussex.
There is slow traffic on A27 eastbound at the Southerham roundabout), with congestion on the A26 southbound.
Delays are reportedly increasing on A27 Ranscombe Hill eastbound in East Sussex. Average speed ten mph.
In Hastings, delays are easing on A21 Sedlescombe Road North southbound between A21 and John Macadam Way.