Statistical assessment of traffic noise patterns and COVID-19 effects

Road traffic noise assessments are based on noise indicators, including, at a minimum, average noise indicators like equivalent sound level (Leq) and single-event noise indicators like maximum sound level (Lmax). In the absence of guidance from regulatory agencies as to how these indicators should be defined and measured, previous work has included proposed definitions and methods for estimating the noise indicators and determining the uncertainty and reliability of the estimates. The analyses were based on statistical analyses of time history noise levels recorded at various cities across Connecticut and California as well as Dublin, Ireland [King et al., Noise-con (2016)]. Previous work suggested that the observed patterns and methods were broadly applicable across a wide variety of road types and cities, based on measurements performed at different locations. The dramatic changes in traffic due to the COVID-19 pandemic allowed analysis of the effect of changing traffic volumes and diurnal patterns on the time history levels at given locations. This paper describes the effect of the pandemic on traffic patterns and what this demonstrates about the variability and robustness of the statistical estimation methods.