Precautionary treatments are normally completed in less than 3 hours for each route and at least 1hr in advance of forecast road hazards forming.
Fel arfer, caiff triniaethau rhagofalus eu cwblhau mewn llai na 3 awr ar gyfer pob llwybr ac o leiaf 1 awr cyn i'r peryglon ffyrdd a ragwelir ffurfio.