The data, which was collected by Transport for Wales, monitored millions of vehicles’ speeds in nine different communities across Wales before and after implementation.
Roedd y data, a gasglwyd gan Trafnidiaeth Cymru, yn monitro cyflymder miliynau o gerbydau mewn naw cymuned wahanol ledled Cymru cyn ac ar ôl i'r terfyn gael ei roi ar waith.