Dros y 30 mlynedd diwethaf, amcangyfrifir bod dros 370 miliwn o gerbydau wedi teithio dros yr uniadau hyn ers i’r draphont gael eu hagor ym 1991. Mae'r uniadau ehangu mawr ym mhen dwyreiniol y bont wedi treulio erbyn hyn a rhaid rhoi gosod rhai newydd yn eu lle.
Over the past 30 years, it is estimated that over 370 million vehicles have passed over these bridge joints since the opening of the viaduct in 1991. The large expansion joints at the eastern end of the bridge are now worn out and must be replaced.