Gatwick Interchange

The Gatwick Interchange is a partially signal controlled roundabout forming junction 9 of the M23, connecting it to M23 Gatwick Spur.

The junction and the link road to Gatwick Airport was opened on 23 April 1975, slightly later than the 19 December 1974 opening of M23.

Smart Motorway Upgrade

During 2019/2020 the M23 was upgraded to a smart motorway between J8 with the M25 J7 at Merstham and J10 with the A2011 and A264. This upgrade turned the hard shoulder into a permanent 4th running lane, however this junction is a lane drop/gain.

The M23 Spur which comes off of this interchange also had its hard shoulder westbound (airport bound) converted into a 3rd permanent running lane as well as a free-flow slip roads to and from the M23 Northbound.

Traffic lights on the northbound off-slip have also been removed. So lane 1 of the off-slip goes free-flow directly onto the M23 spur, and Lane 2 gives way to traffic on the Gyratory. However this isn't clearly signed and is open to confusion that one lane goes where everybody wants to go and the other lane, for reasons that are unclear, takes a longer route.

Traffic lights are still in place at the top of the southbound off-slip, and eastbound traffic still needs to stop and give way to the redundant section of roundabout.

Routes

Route	To	Notes
M23	London, (M25), Dartford, Heathrow Airport
M23	Brighton, Crawley, E. Grinstead (A264)
M23	Gatwick Airport North & South Terminals, Redhill	M23 Spur, leading into the A23 Spur which connects to the A23