Smart Motorway gantry sign
A gantry structure spanning the motorway with electronic signals, blue signs showing a "tiger tail lane drop" where the left lane exits, the right hand two lanes continue ahead and the second lane from the left can go in either direction, and the following text.
Exit destinations: (A23) [Solid square diversion symbol] ; Redhill, Gatwick [Airport symbol].
Forward destinations: London M23.
Junction number: 9.
Change Route: M23 Gatwick Spur
It's about to get significantly busier. One of the M23's main jobs is linking Gatwick Airport to the M25, so a lot of traffic is about to come down the sliproad from junction 9 and join us, and almost all of it is going to leave again at junction 8.