Smart Motorway gantry sign
A gantry structure spanning the motorway with electronic signals, blue signs showing the left lane exiting and three others continuing ahead, and the following text.
Exit destinations: A2011 [Hollow square diversion symbol] ; Crawley; A264 [Solid square diversion symbol] ; East Grinstead.
Forward destinations: Brighton, Horsham M23.
Junction number: 10.
Crawley and East Grinstead are major commuter towns for London, but also important places in their own right. You might think of Sussex as a rural county but there's a lot of people just off this junction.