There are reports of a crash on Kingspit Lane near Riverhill Lane, the AA said. Traffic is coping well.
There is a lane closed due to water main work on the A259 High Street around the A283 Old Shoreham Road (The Bridge Inn roundabout).
The B2095 Lower Street is shut both ways between the A269 Bexhill Road and the Bexhill Turn off, due to construction work.
Trains are currently unable to run between Haywards Heath and Lewes due to a fault with the signalling system, Southern Rail said.
A spokesman added: “Where possible, services will be diverted via Brighton.
“Please check journey planners before travelling and allow up to an extra 20 minutes.
If you’re travelling to Plumpton or Cooksbridge, please speak to station staff at Haywards Heath, Brighton or Lewes for assistance with onward travel.
“If you’re travelling to Lewes or Haywards Heath, your journey time will be extended by at least 30 minutes.
“If you’re waiting for a train at Plumpton or Cooksbridge, please press the green emergency help point button for assistance with onward travel.”