Reliable methods for low frequency map to improve action plans

After the first implementing round of Directive 2002/49/EC, different experiences pointed out the need of a reliable method of mapping. To this aim, JRC coordinated CNOSSOS methodology setting-up, which still lacks of implementation. Furthermore, experiences of action plans show that not all actions really improve noise quality when reducing only noise energy. In fact, the contribution of low frequencies in left shifted road spectrum noise (by barriers, new pavements, etc) can determine a lot people annoyance, which doesn't appear so reduced. Therefore, in this study, a map will be proposed using the most reliable method available (NMPB 2008, Nord2000 and ISO9613 modeling methods will be compared): it will be based upon measurements carried out in order to verify not only the overall A-weighted level but also the spectrum estimation as it is proposed within CNOSSOS methodology. We intend to estimate the LC- A indicator (used within occupational noise protection laws to evaluate damage to health), which is considered to be suitable to evaluate annoyance due to low frequency content. The aim is to show correlation between LC- A hot spots and annoyed people. This test has been carried out in Pisa where an accurate evaluation of traffic flows was already available. Copyright © (2013) by Austrian Noise Abatement Association (OAL).