It has the highest proportion of all trunk roads (27.3%), B and C roads (21.0%) and minor surfaced roads (12.3%) and accounts for 15.7% of the total road length of Wales.
Mae ganddi'r gyfran uchaf o'r holl gefnffyrdd (27.3%), ffyrdd B ac C (21.1%) a mân ffyrdd wyneb (12.0%) ac mae'n cyfrif am 15.7% o gyfanswm hyd ffyrdd Cymru.