THE IRISH National Roads Authority (NRA) has decided to limit the use of stone mastic asphalt as a road surfacing material after fears about the material's skid resistance properties.
Irish local authorities have been ordered to limit the use of the material to 30mph zones.
Problems came to light on two new roads near Dublin after inspections by NRA engineers.
'We found that the texture of the road surface was wearing faster than expected and that the skid resistance was also declining, ' NRA corporate affairs manager Michael Egan told NCE.
He said that manufacturers would have to provide reassurances before the NRA would consider lifting its restrictions.
'In general, it will not be used outside 30mph areas until we are satisfied with regard to surface texture performance and lifespan, ' said Egan.
He added that there were no safety concerns at present, and any decrease in skid resistance below safe levels would be picked up by routine Scrim testing and inspection.
But concerns over the longevity of the material and the risk that having to resurface early are believed to have prompted the partial ban. The material has only been used in the past two years in the Republic over 53.7km of national roads - around 1% of the total.
New roads laid with stone mastic asphalt could be slippery when dry according to researchers.