There are huge delays in Crawley following a three-vehicle collision this afternoon.
Police confirmed that a lorry and two cars collided on the southbound carriageway, which was closed, at about 3.50pm today (Wednesday, May 1).
A woman has been airlifted to hospital with injuries – read more here.
The northbound carriageway reopened at 5.35pm but the southbound carriageway remains closed.
According to travel reports, there is congestion to four miles before junction nine (Gatwick Airport).
Traffic diversions are also causing congestion on routes through Crawley, Blindley Heath, Felbridge, Turners Hill, East Grinstead, Handcross, Balcombe, Godstone and around Gatwick Airport.
Highways England is reporting long delays of up to 60 minutes.
For more information on the diversions in place, see the Highways England website here.
Drivers are being advised to avoid the M23 at Crawley if possible.
Anyone who saw what happened is asked to contact Sussex Police online or by calling 101, quoting Operation Stonewall.