The National Roads Authority has instructed local authorities to mix salt with sand so that supplies can be maintained.
Some local authorities are using up to five times their normal amount.
NRA spokesman Sean O'Neill said the move was to make sure that the national road network remained open.
The authority has 30,000 tonnes of salt left and is expecting to get more deliveries to bring it up to 50,000 tonnes by Christmas.
Commuters have been warned to expect delays and curtailments to services as severe weather conditions continue.
Iarnród Éireann and Bus Éireann said they are attempting to run a full schedule, however Dublin Bus has been forced to cancel some routes.
Dublin airport is open but flights are experiencing delays and passengers are advised to check their airline's website before travelling to the airport.
Gatwick Airport in London is open after a two-day closure caused by heavy snow.
Motorists are once more being advised to exercise extreme caution and avoid travel if possible.
Council gritters are trying to clear main roads but black ice, compacted snow and fresh snow are making secondary roads treacherous throughout the country.
Many national and secondary schools and third-level institutions are closed again today.
It is estimated that one worker in five is staying out of work or working shorter days because of the conditions.
Employers' group IBEC estimates that hundreds of millions of euro has been lost as a result of the cold weather.
However, it hopes that much of that can be recovered if business returns to normal in the coming weeks.
The Taoiseach has acknowledged the efforts of all workers during the current severe weather.
Brian Cowen today issued a statement today thanking local authority, healthcare and public transport workers, gardaí, the Defence Forces, and Civil Defence Personnel for all their work during the cold snap.
Temperatures are set to dip to -6C tonight with further snow, sleet, rain, frost and ice forecast for the weekend.
Met Éireann has also warned there will be freezing fog and temperatures will stay very low.