The Order will impose a 40 mph speed limit and derestrict to the national speed limit lengths of the A4060 trunk road between Abercanaid Roundabout and Dowlais Top Roundabout, Merthyr Tydfil.
Bydd y Gorchymyn yn gosod terfyn cyflymder o 40 mya ac adfer y terfyn cyflymder cenedlaethol ar ddarnau o gefnffordd yr A4060 rhwng Cylchfan Abercannaid a Chylchfan Dowlais Top, Merthyr Tudful.