However, in cases where the criteria yield mixed results, engineering measures could be implemented to support an increase from a 20mph speed limit to 30mph.
Fodd bynnag, mewn achosion lle mae'r meini prawf yn arwain at ganlyniadau cymysg, gellid rhoi mesurau peirianneg ar waith i gefnogi codi'r terfyn cyflymder o 20mya i 30mya.