Evaluation of a pavement surface renewal for urban traffic noise abatement

Road traffic noise is considered the most predominant source of outdoor noise pollution in cities, where control and abatement at the source of this phenomenon is generally more cost-effective than other measures. However, few studies have treated in depth the effectiveness of abatement measures against traffic noise in an urban environment. This paper, based on a field study in a stretch of a busy street in Madrid, an area with high levels of traffic noise exposure in accord with the Strategic Noise Map, aims to evaluate the effectiveness of a pavement renewal as a traffic noise reduction measure in a big city. To this end, a monitoring method of the surface based on continuous and georeferenced measures of the surface profile and sound emissions from the tyre/pavement interaction, have been employed. The field measurements were carried out before and after surface rehabilitation with a bituminous mixture in a section with a speed limit of 50 km/h. A large number of vertical displacements of the profiles and sound signals were processed using frequency analyses to reveals the characteristics of the source of noise along the urban infrastructure, and to evaluate the noise reduction obtained with this abatement measure acting on the source of noise. The results indicate that pavement surface renewal in urban environments can be a corrective measure to mitigate traffic noise inside a city; considering only the most significant source of emissions, the number of people exposed above 55 dB(A) would be reduced by more than 80 % compared with the previous scenario before the resurfacing. In addition, the analysis of the power spectral density of the vertical profile data on the street, showed that the origin of this noise reduction could be associated to the surface characteristics of the pavements before and after its renewal.