The M4 corridor around Newport between Junctions 24 and 28 is the busiest section of road in Wales and carries in the region of 100,000 vehicles every day.
Coridor yr M4 o amgylch Casnewydd, rhwng Cyffordd 24 a Chyffordd 28, yw’r ffordd brysuraf yng Nghymru ac mae tua 100,000 o gerbydau yn ei defnyddio bob dydd.