Rail noise comparison of FTA methodology with CadnaA modeling at Bronx development site

For environmental studies, identifying road and rail noise is important in projecting potential impacts from increased operations and also in identifying the window/wall attenuation needed to reduce outdoor to indoor noise levels. The Federal Transit Administration's (FTA) transit noise and vibration impact assessment procedures provide spreadsheets for estimating noise levels at specific receptor points. However, computer models such as SoundPLAN and CadnaA are also available. Because these computer models have complex input requirements and account for local terrain, they are rarely used for large corridor studies, but they are well suited to smaller sites. This study compares the FTA procedures with CadnaA modeling at a development site in the Bronx, NY, that is bounded by multiple rail lines and is proximate to a major highway. Discussion of results presents the advantages and disadvantages of each approach and identifies the conditions under which each approach is most appropriate.