Smart Motorway gantry sign
A gantry structure spanning the motorway with electronic signals, blue signs showing an exit and the following text.
Exit destinations: A54 Chester, Northwich; Middlewich .
Forward destinations: NORTH WALES, Preston, L'pool; Manchester, [Airport symbol] M6 .
Junction number: 18.
You'll pass Chester if you want to reach North Wales, so it's not entirely clear why they're signposted in different directions. I'd be inclined to stay on the M6 a bit longer for Chester, but the scenic route via Middlewich has its charms.