Under the Regulations, TII is responsible for the development of strategic noise maps for all national roads carrying in excess of 3 million vehicles a year and for light rail lines (i.e. the Luas network) which has more than 30,000 passages per year.
For the 2017 phase of noise mapping, strategic noise maps were developed for over 3000 km of national roads. Additional strategic noise maps were also developed by TII for major non-national roads. However, major non-national roads mapped by TII remain under the jurisdiction of the relevant local authority.
Under Round 2 strategic noise mapping completed in 2012, all operational Luas lines exceeded the threshold of 30,000 train passages per year and thus, all operational Luas lines were mapped under Round 2. A comprehensive review undertaken by TII determined that there had been no significant changes made to the existing Luas infrastructure nor were there any changes to the operational rolling stock since Round 2 completion. Therefore, TII concluded that they would not be revising Round 2 strategic noise maps undertaken for the Luas network for Round 3 of strategic noise mapping.
In accordance with the Environmental Noise Regulations, the strategic noise maps prepared in 2017 are based on road and light rail traffic movements in the calendar year 2016. Therefore, for example, strategic noise maps were not prepared for the M17/M18 Gort to Tuam motorway and Luas Cross City as both schemes opened in 2017.
The website displays noise maps for major roads outside the agglomerations of Dublin and Cork. These maps were developed by TII in 2017. The 2012 strategic noise maps developed for the Luas network within Dublin are also displayed.
What is a Strategic Noise Map?
A strategic noise map is a graphical representation of the predicted situation with regards to noise in a particular area with different colours representing different noise levels in decibels [dB(A)].
To develop a noise map a number of variables must be determined in order to correctly represent the amount of noise generated at the source, i.e. by traffic driving on the road or Luas trams travelling on rail. For roads, the noise level at the source is primarily influenced by the speed at which traffic is travelling at, the overall quantity of vehicles in the traffic flow, the proportion of heavy commercial vehicles (HCVs) in the flow and the type of road surface in the area. For light rail, the noise level at source is influenced by the speed the tram is travelling at and the number of trams operating the timetable.
The manner in which the noise propagates away from the source must then be calculated which involves determining the reduction in noise level as it propagates from the source. Distance, ground cover and the presence of barriers such as walls, noise barriers, etc. will all influence the level of noise attenuation.
All noise maps are presented in terms of two noise indicators: Lden and Lnight.
Lden is the day-evening-night noise indicator and it represents the noise indicator for overall annoyance. It is ‘weighted’ to account for extra annoyance in the evening and night periods.
Lnight is the night time noise indicator and is used in the assessment of sleep disturbance.
These indicators are based on year long averages of the day (07:00-19:00), evening (19:00-23:00) and night (23:00-07:00) time periods.
National Strategic Noise Maps
Strategic Noise Mapping 2017 Lden Web Map
Lden is the calculated day-evening-night noise level and represents the noise indicator for overall annoyance. It is calculated over all day-evening-night periods for one year. The day period is from 07:00 to 19:00, the evening period is from 19:00 to 23:00 and the night period is from 23:00 to 07:00. The Lden indicator contains extra weighting for the evening and night periods as noise is generally more annoying during these periods. The map below indicates the Lden decibel (dB) bands report for Strategic Noise Mapping 2017.
Strategic Noise Mapping 2017 Lnight Web Map
Lnight is the night time noise indicator and is used in the assessment of sleep disturbance. It is the average noise level calculated over all night periods, 23:00 to 07:00, for one year. The map below indicates the Lnight decibel (dB) bands report for Strategic Noise Mapping 2017.
Strategic Noise Mapping 2012 Lden Web Map
Lden is the calculated day-evening-night noise level and represents the noise indicator for overall annoyance. It is calculated over all day-evening-night periods for one year. The day period is from 07:00 to 19:00, the evening period is from 19:00 to 23:00 and the night period is from 23:00 to 07:00. The Lden indicator contains extra weighting for the evening and night periods as noise is generally more annoying during these periods. The map below indicates the Lden decibel (dB) bands reported for Strategic Noise Mapping 2012.
Strategic Noise Mapping 2012 Lnight Web Map
Lnight is the night time noise indicator and is used in the assessment of sleep disturbance. It is the average noise level calculated over all night periods, 23:00 to 07:00, for one year. The map below indicates the Lnight decibel (dB) bands reported for Strategic Noise Mapping 2012.
Strategic Noise Maps
Please refer to the table below for strategic noise maps by county.