Smart Motorway gantry sign
A gantry structure spanning the motorway with electronic signals, blue signs showing the left two lanes exiting and the other two continuing ahead, and the following text.
Left-hand two lanes destinations: M4 SOUTH WALES; Chepstow (M48); London; Bristol (M32) [Solid triangle diversion symbol] .
Right-hand two lanes destinations: The SOUTH WEST; Bristol (W) & [Airport symbol]; Filton (A38) [Solid square diversion symbol] M5 .
Junction number: 15.
Change Route: M4 SOUTH WALES & London
Three lanes widen to four as we approach Almondsbury Interchange, the UK’s first four-way motorway interchange and its first four-level junction. Exit here for all things M4.