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: A38 [Solid triangle diversion symbol] [Solid circle diversion symbol] ; Thornbury; Filton.
Forward destinations: SOUTH WALES (M4 (W)) [Hollow square diversion symbol]; London (M4 (E)); The MIDLANDS, Gloucester M5.
Junction number: 16.
We’re now approaching the combined junctions 16 and 15, which together connect the M5 to the local road network and to the M4. The real sign here is fabulously complex, splitting traffic into different lanes for the A38, M5 and different directions on the M4.