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: A3 ; Portsmouth; Guildford; London (SW); Kingston.
Forward destinations: (M3, M4, M40), Heathrow [Airport symbol]; Woking (A320), Watford M25 .
Junction number: 10.
This is one of the busiest interchanges on the M25, which is unfortunate because it's just a big signalised roundabout sandwiched between the M25 and A3. Left turners can zip past it without too much trouble but right turners will need to pass through several sets of traffic lights.