All lanes have now been re-opened but drivers face delays of up to a 70 minutes following a collision on the M23 near Gatwick this lunchtime (Tuesday June 12) which is also affecting the M25.
Two lanes were closed due to the incident which reports say involved four cars.
It happened on the motorway southbound between junction 8 and 9.
Lanes two and three (of three) were closed heading south towards Gatwick Airport.
Traffic has also been queueing on the M25 in both directions around junction 7 as drivers try to join the M23.
Vehicles have been recovered on to the hard shoulder but it will take a while for the traffic build-up to clear.