Implementing the CNOSSOS-EU correction near traffic light junctions and roundabouts

Under the Environmental Noise Directive (END), the Round 4 strategic noise maps are to be calculated using the methodology set out in Directive 2015/996 (as amended) (CNOSSOS-EU). As part of the road traffic source emission model, a correction for the effect on noise levels due to the acceleration and deceleration of vehicles shall be applied near crossings with traffic lights and roundabouts. As part of the revision of the EPA guidelines on strategic noise mapping in Ireland, a technical investigation was carried out to identify the effect of the correction factor on road traffic noise emissions, and determine whether there was a practical approach to implement the correction factor within the upcoming noise mapping. This paper will provide an overview of the results, including the change in noise level emissions for low speed low flow roads, and high speed high flow road. It will also present a practical approach to preparing the road traffic flow models in GIS based on available datasets.