The M23 northbound is closed for the entire weekend between junction 10 at Crawley and junction 9 at Gatwick Airport.
The closure will be in place all weekend and for next three weekend for resurfacing by Highways England, from 10pm on Friday to 4am Monday.
In addition, no trains are running between Three Bridges and Brighton or Lewes because of engineering works.
Replacement buses are operating and some trains between Three Bridges and Brighton will divert via Horsham.
People travelling to and from Gatwick airport have been told to allow extra time for their journey.
Elsewhere on the roads, a 24-hour speed restriction of 50mph is in place all weekend for much of Chichester A27 while the Stockbridge footbridge is being replaced.