Motorway gantry sign
A gantry spanning the motorway with blue overhead signs showing the following text.
Forward destinations: Caerfyrddin; Carmarthen Castell-Nedd; Neath M4 .
Exit destinations: A483 Abertawe; Swansea [Ferry symbol] .
Junction number: 42.
Right at the top of the bridge, a sliproad dives away to the left, meeting the start of the A483, one of the longest roads in Wales. It traverses the country from south west to north east, ending in Chester. We'll meet it twice more before it gets going cross-country.