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: A127 ; Southend; Basildon; London (E&C); Romford.
Forward destinations: (M11, M1), Chelmsford (A12); Stansted [Airport symbol] Watford M25 .
Junction number: 29.
Here's the A127 Southend Arterial Road, a 1920s main road linking East Londoners to their preferred seaside getaway. It still serves the same purpose today.
The M25 from here to J27 at the M11 opened in April 1983, four months after the length we just drove. The early 80s saw a rush of M25 projects all opened in the space of a few years, in which time the few existing fragments around the edges of London started to join into useful sections of ring road.