The National Roads Authority has voiced safety concerns about a surface material used in several recent road projects.The authority has told county councils that the material, stone mastic asphalt (SMA), is to be used in future only on roads with speed limits of 30 miles per hour.
The restriction was applied after potential skid-resistance problems were identified in a number of locations.
The material was used on the Moone-Timolin bypass in Co Kildare and a four-mile stretch of the Dublin-Galway road near Enfield.
A spokesman for the NRA said the material was safe when manufactured and laid according to the correct specifications, and this had been done in all major road projects.
The problems, he said, had been encountered in a number of "local instances" in which the material had not been manufactured or laid properly. It was decided as a precaution to stop using the material on non-urban roads.
Concerns about the safety of SMA, which is cheaper to make than material traditionally used in Ireland, have also been expressed in Britain. Tests commissioned last year by Derbyshire County Council, following two car accidents, identified skid-resistance problems when the surface was newly laid.
Derbyshire is currently erecting signs at locations where SMA was laid in the past year, warning motorists of the danger, a spokesman told The Irish Times.
The signs say "Slippery Road on New Surface". Other local authorities in Britain, where SMA is more widely used than in Ireland, were being informed of the council's findings, he said.
The NRA spokesman rejected the suggestion that this should be done in Ireland.
"If there was a problem with a road we would resurface it, not put up signs telling people 'You're driving on a skating rink'," he said.
In a memo circulated to each county and city council in November, the NRA's head of project management and engineering, Mr Eugene O'Connor, said a recent survey had revealed a problem in relation to the surface texture of SMA.
"A significant proportion of the completed questionnaires returned by the local authorities indicates that the laid material has failed to achieve or retain adequate texture depth," he wrote.
In the light of that and in the interests of road safety the use of SMA on national roads should be restricted to locations within the 30 m.p.h. speed limit.
A spokesman for the NRA said safety and skid-resistance checks were carried out on all sections of national primary roads each year, and remedial work where necessary. In 2000, 60 kilometres of the national primary roads network was identified as requiring surface dressing, just 2.3 per cent of the total.
