Statistical evaluation of noise due to changes in pandemic traffic patterns

Vehicular traffic noise for free-flowing roadways and highways generally follows statistically predictable flow rates and vehicular mix. The authors’ earlier work in this area examined long-term variations in traffic noise level with the purpose of establishing maximum hourly levels for vehicular sources (“Defining vehicular noise levels to manage risk associated with exterior façade design,” LoVerde, Dong, Rawlings, Internoise 2014 Melbourne) and general average sound level (“Noise prediction of vehicle sources on arterials using measured sound data,” LoVerde, Dong, Rawlings, ASA 2014 Providence; “Methods for estimating the variance in traffic noise distribution from short-duration measurements,” LoVerde, Dong, Rawlings, ICSV 2015 Florence). When the COVID-19 pandemic resulted in lockdowns, traffic patterns at the measurement location in Southern California were affected. The authors’ examination of traffic data revealed that the changes in traffic patterns did not affect noise level significantly, but variability in sound level across the 24-h period increased substantially (“Changes in statistical traffic noise descriptors during COVID-19,” LoVerde, Dong, Edwards, Rawlings, ASA 2021). For this paper, the authors have undertaken comparison of pre-, during-, and post-lockdown vehicular traffic noise levels over a several-month period for the purpose of understanding how measurement of traffic noise is implemented and interpreted.