Empirical Study on Temperature Influence on Noise Measurements with the Statistical Pass-By Method

Road traffic noise measurements, such as the Statistical Pass-By method (SPB) described in ISO 11819-1, are pivotal in assessing this noise pollution problem. As temperature is a primary cause of uncertainty in tyre/road noise measurements, the SPB method results need to be temperature corrected. The ISO 11819-1 standard is currently being revised and will refer to ISO/DTS 13471-2:2021, also in the drafting stage, for a temperature-correction procedure that is not present in the current ISO 11819-1:1997 version. Compared to other methods, little research has evaluated the temperature influence using the SPB method. In this paper, 18 SPB measurements were performed at three locations, with dense asphalt concrete and SMA as the pavement type. In total, over 5700 vehicles were captured, covering the complete temperature range in ISO 11819-1. For passenger cars, a temperature coefficient of −0.103 dB/°C was obtained while no statistically significant proof was found that temperature influences the sound-pressure levels for heavy vehicles at the speeds in this study (45–65 km/h). In this speed range for heavy vehicles, not only the tyre/road noise is a significant source of pass-by vehicle noise but also the power unit noise, on which the temperature influence is more complicated. Additionally, the analysis of various temperatures (air, road and estimated tyre temperature) revealed that the air temperature appears to be best suited for the temperature correction procedure. In third-octave bands, no effect was observed in the low-frequency range for passenger cars, contradicting previous research. Negative correction coefficients were found in the middle and high-frequency range, although trends presented in other studies were not observed.