A public awareness campaign was launched today to prepare motorists for the changeover to metric speed limits in two weeks' time.
From Thursday 20 January, speed limits on Irish roads will change from mph to km/h.
The speed limit on 91% of Ireland's 96,000km of roads will decrease.
The main change will be the lowering of the speed limit on regional and local roads to 80km/h which equates to 50mph.
On the remaining 9%, including motorways and national roads, the speed limit will increase slightly.
Local authorities will be able to apply special speed limits but will have to consult with the public whenever such bylaws are being created.
Over 58,000 speed limit signs will be erected by local authorities in the run-up to the changeover.
The public awareness campaign will involve TV, national and local radio, national and local and fee sheet press, billboard advertising and a dedicated website, www.gometric.ie.
Also 1.6 million special information leaflets are being distributed by An Post to all household and business addresses in the state by 14 January.