Motorway cantilever sign
A blue overhead sign suspended over the motorway from a post on the left, showing an upcoming exit and the following text.
Exit destinations: A45; [Hollow triangle diversion symbol] Northampton; Wellingborough; Kettering (A43) A508; [Hollow circle diversion symbol] [Solid cross diversion symbol] Rail Freight; Terminal .
Forward destinations: London, Milton Keynes M1.
Junction number: 15.
This is one of those junctions that has been remodelled so many times that it's unrecognisable from the thing that was first put here in 1959. It's become something of a Frankenstein's Monster - there are theoretically two roundabouts in there somewhere, but they're recognisable only to their mothers now.