As Minister for Transport, Tourism and Sport, I have responsibility for overall policy and funding in relation to the national roads programme. Once funding arrangements have been put in place with Transport Infrastructure Ireland (TII), under the Roads Acts 1993-2015, the planning, design and construction, including noise mitigation measures, for individual national roads is a matter for TII, in conjunction with the local authorities concerned.
Directive 2002/49/EC on the assessment and management of environmental noise was transposed into Irish law by the Environmental Noise Regulations, 2006. This legislation requires Transport Infrastructure Ireland (TII) and local authorities to undertake strategic noise mapping every five years for all major roads carrying in excess of 8,250 annual average daily traffic (AADT). Noise maps identify and prioritise cluster areas which will require further assessment and may require mitigation measures to be put in place.
Once strategic noise maps have been produced, the results are used for each local authority to develop Noise Action Plans as required by the Environmental Noise Regulations. Under the Regulations, the Noise Action Planning Authorities are required to consult with the public when revising their current Plans.
On foot of the revision of the Dublin Agglomeration Noise Maps in 2017 the four local authorities within the Dublin Agglomeration carried out a review of the Noise Action Plan 2013-2018.
Following on from the review and after public consultation, a finalised revised Action Plan was produced which came into effect in December 2018. This plan is a continuation of the 2013-2018 Noise Action Plan and sets out broad principles and actions to mitigate excessive environmental noise and protect areas of good acoustical quality within the Dublin Agglomeration.
Specifically in relation to the M50, I have referred your question to TII for a more detailed and direct reply. Please advise my private office if you do not receive a reply within 10 working days.