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: M11 Cambridge, Harlow; Stansted [Airport symbol]; London (NE & C) .
Forward destinations: (M1, M40, M4), Watford; Heathrow [Airport symbol] M25 .
Junction number: 27.
A hugely important interchange with one of the main roads north, and another opportunity to find East Anglia if the A12 didn't suit you. Heathrow has just made its debut on the signs - a third of a circuit away yet.
The next length of M25, from here to J25, opened in January 1984, about eight months after the last section, and closed a gap between two existing lengths. Its opening made it possible to drive from the Dartford Tunnel to the A1 by motorway.