1. Introduction
Noise pollution is one of the transportation externalities in urban areas, causing discomfort, annoyance, and displeasure
for the exposed population (Basner et al., 2014). The results from the first phase of the strategic noise mapping in the European
Union (EU), which occurred in 2007, suggest that approximately 56 million people are exposed to environmental noise
above 55 dBA during daytime from road traffic within agglomerations, while 33 million are exposed to noise from major
roads outside agglomerations. Additionally, approximately 40 million people across the EU are exposed to noise above
50 dBA from roads within agglomerations during the night, and 22 million are exposed to outside agglomerations
(Murphy and King, 2014). These results are very worrying from a public health perspective, given that the World Health
Organisation (WHO) sets 40 dBA as the nighttime level at which health effects are noticeable (Hurtley, 2009)