Accuracy of Temporal Samplings of Non-urban Road Traffic Noise

The legislation on road traffic noise often requires the determination of its acoustic descriptors on medium or long-term. The available instrumentation enables to perform such measurements as they can store and transmit a huge amount of data. However such duration is not feasible for attending monitoring and, therefore, requires the time-consuming post processing validation of the acquired data. On the other hand, use of temporal samplings enables attended monitoring and avoids the data validation, as well as improving the spatial resolution of sampling. However, the estimated values of the noise descriptor are affected by inaccuracy which depends on the ratio between the total measurement time and the long term, as well as on the variability of the noise immission at the receiver. The paper describes the results obtained from the statistical analysis of LAeq data taken from continuous monitoring at several sites alongside the network of non-urban roads in the Lombardia region in Italy. The accuracy of the following sampling rates: 1) 5, 10, 15, 20, 30 minutes for the estimate of hourly LAeqh; 2) LAeqh for estimating the LAeqday and LAeqnight; have been determined considering the traffic flow too.