To maximise efficiency and reduce the time taken to salt the roads, the gritter has to travel across some intersecting roads to be able to salt the primary roads.
Er mwyn bod mor effeithlon â phosibl a lleihau faint o amser a gymer i raeanu'r ffyrdd, mae'n rhaid i'r lori graeanu groesi ar hyd rhai ffyrdd eraill er mwyn cyrraedd y ffyrdd pwysicaf i'w graeanu.