On 17 September 2023, the Welsh Government introduced a 20mph speed limit on most roads that were previously 30mph, mainly in residential and busy pedestrian areas with street lighting.
Ym mis Ebrill 2024, cefnogodd y Cyngor Sir y Rhaglen Wrando Genedlaethol drwy lansio tudalen we bwrpasol lle gallai pobl ofyn am adolygiad o derfynau cyflymder 20mya ar rannau penodol o ffyrdd.