Snow was causing delays and disruption to commuters today (Tuesday March 12) and last night, leading to bus and train cancellations.
The A22 at Millbrook Hill, Nutley, across the Ashdown Forest is generally impassable, although 4x4s are getting through with care.
The A22 is also closed both ways as a result of hazardous driving conditions with ice and snow between the A26/Lewes Road (Halland) and A275 Lewes Road (Wych Cross, Wych Cross).
There are a number of abandoned vehicles. Cars are being advised to use the A275.
The A259 Eastbourne Road remains closed both ways due to hazardous driving conditions.
There is ice and snow between Seaford and B2103 Warren Hill/Beachy Head Road (Eastbourne).
Conditions have been treacherous since yesterday.
At this stage it looks set to continue snowing in the Lewes area until around lunch time, with temperatures ranging between -1C and 1C.
Due to wind chill it could feel as cold as -7C.
The railway line between Redhill and Tonbridge is currently blocked and due to impassable roads Southern is unable to provide replacement buses on this route.
All other Southern lines are open but subject to short notice alterations, some cancellations and delays of up to 60 minutes.
Brighton and Hove Buses, which serves Lewes, Uckfield and Seaford, has only just starting running the number 7 bus in Brighton - there are no other Brighton and Hove Buses vehicles running at this time.
A statement on the bus company’s website said: “All of our other bus services are currently withdrawn due to the atrocious weather and road conditions.
“We have been out checking roads all morning to see whether we can get some bus routes running.
“As well as the road itself being clear we need to make sure that buses have somewhere to turn round if they cannot reach their normal terminus, and this is often difficult if side roads are badly affected by snow, ice and abandoned vehicles.
“We have over twenty buses stuck throughout the city and our teams are attempting to recover them, and many roads are blocked by abandoned cars.
“We sincerely apologise for any inconvenience caused. We want to get buses running again and will resume more services just as soon as we are able.”
If you hold a valid Saver bus ticket you will be able to use it on the train in the local area, as well as to and from Lewes, Seaford and Eastbourne.
Keep up to date with the latest developments on www.southernrailway.com and http://www.buses.co.uk/
Compass Travel, which also operates bus services in East Sussex, said it was monitoring road conditions, but that currently it was not safe to travel.
Last night commuters were caught out by snow flurries which led to difficult driving conditions and caused hundreds of collisions.
Sussex Police were assisting drivers stuck across the county due to the adverse weather conditions on Monday March 11 during the evening rush hour.
Inspector James Biggs from the Road Policing Unit said the worst areas were parts of the A23 and M23 particularly around Handcross Hill.
Many drivers had to be rescued from their cars and were stuck in their vehicles for hours.
Yesterday evening the M23 and A23, Pyecombe and Handcross Hill were gridlocked, with gritters working to clear it.
In East Sussex the A21, A22, A26 and A27 were passable but very slow, while in West Sussex the A27 was closed at Worthing, as was the A29 at Bury Hill.
The A259 was shut at Beachy Head during the afternoon.