According to traffic reports, one lane is closed and there is queueing traffic northbound, between J10A B2036 Balcombe Road (Crawley South / Balcombe) and J10 A264 Copthorne Way (Crawley).
Lane one – of three – is shut.
Meanwhile, there are reports of a collision on the A22 at Polegate.
Traffic reports say the collision happened southbound near the A27 Polegate bypass (Cop Hall Roundabout).
Police are said to be on the way to investigate.
If you are travelling by train today, there are planned engineering works on the Southern network.
Routes to London Victoria are affected and most services will be diverted to run to and from London Bridge instead.
And services between London and Uckfield will run between East Croydon and Uckfield only.