Mae Llywodraeth Cymru wedi ymrwymo i leihau gwrthdrawiadau ac anafiadau ar y ffyrdd, a datblygu amgylcheddau mwy diogel i bawb sy’n defnyddio’r ffyrdd, o fewn system ffyrdd sy’n cryfhau cymunedau gwledig ac sy’n helpu i wireddu amcanion economaidd, cymdeithasol ac amgylcheddol ehangach.  Mae gan derfynau cyflymder ran bwysig iawn i’w chwarae o ran rheoli cyflymder yn effeithiol ac annog, helpu a gorfodi defnyddwyr ffyrdd i deithio ar gyflymder addas a diogel.
The Welsh Government is committed to reducing road traffic collisions and injuries, and developing safer environments for all road users, within a road system that strengthens rural communities and aids wider economic, social and environmental objectives.  Speed limits play a fundamental role in effective speed management designed to encourage, help and require road users to adopt appropriate and safe speeds.