This street atlas, scale 4 to 1 mile (1:15,840), extends to Barry, Caerphilly, Caldicot, Chepstow, Cwmbran, Penarth, Pontypool, Pontypridd and Caerleon. Grid squares are based on National Grid, the values for which are shown in the margin. A separate index to places and areas is included. Alterations to this edition include: 2H15-5H15 - North Pentwyn Link Road is shown as open; 6D30-4B34 - Butetown Link is shown as open; 4B44-6D44 - Pontypool Western By-pass is shown as open, the old route has been downgraded to a minor road; 5H51-1F57 Brynglas Tunnels and Malpas Road relief road is shown as open; 1A52-4A52 - Llantarnam By-pass is shown as under construction.