Motorway cantilever sign
A blue overhead sign suspended over the motorway from a post on the left, with a diagonal arrow pointing up and left, and the following text.
A111 Potters; Bar .
Junction number: 24.
The next length of motorway, J24-23, first opened in 1976, making it one of the oldest parts of the M25. However, when it first arrived, it was in disguise as the A1178, only becoming a motorway in February 1984.