The proposed new drink-driving limits will not be introduced before mid-2011 because the equipment used to test breath samples from drivers must be replaced.
Speaking on RTÉ's Morning Ireland, Denis Cusack, Medical Bureau of Road Safety, explained that equipment used at the moment was ten years old and coming to a stage where it must be replaced.
He said that recalibrating the present instruments to incorporate the proposed new drink-driving levels would take eight to nine months, and these would have had to be replaced within two to three years.
A decision has now been taken to purchase new equipment, which will include safeguards required under the Constitution.
This equipment will be in place in 2011.
Minister for Transport Noel Dempsey has said there is no way to speed up the process.
He said that because of the highly litigious nature of current road traffic laws, time would be needed to ensure the new equipment and the procedures for using it were watertight.
In a statement the Department of Transport said: 'The minister asked the Medical Bureau of Road Safety to consider the operation of the measures in the new Road Traffic Bill.
'The Bureau has set out a programme explaining how this should be procured. The Department of Transport will ensure speedy provision of this new equipment.
'It is crucial to ensure that the operation of the analysis machinery is robust. Due to the highly litigious nature of road traffic law in Ireland, it is vital to ensure that the new equipment and procedures are watertight.'
The new Road Traffic Bill published on 30 October reduced the blood alcohol limit from its current level of 80mg/100ml to 20mg/100ml for learner, novice and professional drivers, and to 50mg/100ml for other drivers.
Breath testing will also become mandatory at the scenes of crashes.
Those whose blood-alcohol level falls between the old and new limits will be given three penalty points rather than an automatic disqualification.
