A blue sign with a diagram showing a motorway junction roundabout, with exits left and right, and the following text.
Left turn destinations: SOUTH WALES; Cardiff; Newport; M4w.
Right turn destinations: London; Bristol; M4e.
Change Route: M4 SOUTH WALES or M4 London
That’s it - the end of the line! Most traffic turns left here, since a right turn gets you back to the M5, which we only left a few miles ago.