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This paper describes a new method developed within the BEEP project (Big data for Environmental and occupational EPidemiology) to estimate road traffic flows and to improve the truthfulness of noise maps for agglomerations through Big Data treatment. This new approach, based on data provided by Google API, acquires information regarding travel time to estimate traffic volumes using link delay functions. To achieve this goal, an appropriate experimental plan was designed to simultaneously collect travel times by Google Application Programming Interface (API) and traffic volumes on site. The experimental survey, carried out in the cities of Rome and Pisa, involved different types of road links with traffic lights or roundabouts and different number of lanes. The influence of link characteristics on the correlation between travel time and traffic flow was analysed. The method developed was used in a small area of the city of Rome, and noise maps derived by Big Data were compared to noise maps produced via conventional means.

A loudspeaker can be seen as a device coupling different acoustic, mechanic and electric systems by a series of impedance adaptations. A simple model can thus allow the determination of the acoustic impedance seen by the speaker membrane from measuring the electric impedance of the device. Given a certain number of assumption on mechanical modes and on the strictly electric components, this approach in principle is valid through a wide frequency range. Applying this method with a loudspeaker or a similar device allows to perform acoustic impedance measurements, as shown by Ahadi and Bakhtiar in a previous work. Unfortunately, when trying to apply straightforwardly this method, many difficulties arise. In this paper, using a FEM simulation of a loudspeaker in specific mounting conditions, critical aspects are highlighted to improve the range of application of the measurement technique. Moreover, the role of the speaker’ s geometry is separately analysed and possible methods to overcome the limitations of the measuring method are provided. Further developments will be necessary to deal with time varying and nonlinear properties of the speaker.

The usage of low-noise road surface can be an important and effective noise mitigation action and, in many cases, it might represent the only viable solution. After the laying of a low-noise road surface, it is necessary to verify if the planned objectives have been actually obtained: the Close Proximity Method (CPX) could be a possible method to achieve this result. The current release of the ISO 11819 draft regarding CPX redirects to a future third part for all details about the reference tyre to be used, while the previous one gave indications on dimensions, kind of tread pattern and maintenance conditions. As well known, tyre dimensions and tread pattern are the main sources of variability of rolling noise. Even though many tyres available on the market comply with all ISO requirements, the choice of a brand or a model rather than another one could nevertheless influence results of measurements. In this work, results obtained in several measurement sessions, repeated using different tyres, are compared, aiming to analyse the influence of the tyre choice in assessing the acoustic performance of a low-noise road surface. Limitations and advantages of the CPX method in regards to the evaluation of the effectiveness of a noise mitigation action are reported, and new perspectives are suggested, in order to improve the relationship with the noise level reduction at the receiver.

The use of road surfaces with low noise emission characteristics is one of the actions mostly applied all over the world to decrease the number of road traffic noise annoyed people. Since many Italian roads are going to be paved with such surfaces, the LEOPOLDO project (funded by the Tuscany Region and the Italian Ministry of Transportation) was planned to check the efficacy in time of this action. Among all solutions, rubberized road surface is one of the most applied in USA, Canada, Europe and Asia. This paper describes results obtained by monitoring four rubberized surfaces one year after the laying and by evaluating the time stability of LEOPOLDO one by means of the Close Proximity method (CPX). All surfaces here analyzed are laid in real scenarios, so the actual efficacy of this action is evaluated. The results on the LEOPOLDO surface show spatial homogeneity, a good time stability and a significant noise emission reduction. Instead, analysis of the four rubberized surfaces shows variability in the results, probably due to the pavement installation quality, as supported by the data. Thus, the rubberized road surface looks to be a very efficient mitigation technology, providing the installation have been carried out with care and proficiency. 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license

The European Noise Directive 2002/49/EC requires to draw up noise action plans. Most of the implemented solutions consist in using barriers, even if some studies evidenced that annoyance could increase after their installation. This action dumps the high frequencies, decreasing the masking effect on low ones. Therefore, people annoyance and complaints may increase despite the mitigation. This can happen even in pedestrian zones near main roads due to the screening effect of first buildings row. In this paper, the authors analyze the post-operam screening effects in terms of low frequency noise. The difference between C- and A-weighted levels is calculated as annoyance indicator (LC-A). Different methods able to map noise with octave bands detail are tested in order to establish differences in the estimates of annoyance exposure. In particular, a comparison is carried out between data from interim method NMPB 96, its updated version 2008, NORD 2000 and those provided by a customized procedure through ISO 9613 propagation and Statistical Pass By measurements. Test sites are simulated in order to validate each model results through measurements. Results are discussed for real locations in Pisa city center and virtual scenarios in a rising scale of complexity.

The Close Proximity Index (CPX) measurement method is proposed in the ISO/DIS 11819-2:2011 and it aims to evaluate different road pavements with respect to their influence on traffic noise, under conditions when tyre/road noise dominates. In this paper, a modified CPX-based methodology is presented, in order to improve the usefulness of tyre/road noise measurement in the evaluation of acoustical performances of a road surface, in terms of both temporal and spatial stability and in terms of effectiveness of a mitigation action. In particular, the proposed methodology uses a finer spatial resolution and improves the speed-levels relationship knowledge. Moreover, data variability and uncertainty related to tyre/road noise measurement results are here investigated. This paper is conceived within LEOPOLDO project, developed in Tuscany with the aim to study the acoustical characteristics of six new experimental road surfaces, and the proposed methodology has been applied to some of them. The evaluation of the local possible acoustical inhomogeneities of test pavements and a three years long monitoring of the time evolution of their acoustical performances were required by the project. Finally, a new criterion is proposed to make more reliable comparisons (differential criterion) between different road surface types and to better evaluate the temporal evolution.

In almost all urban contexts and in many extra-urban conurbations, where road traffic is the main noise pollution source, the use of barriers is not allowed. In these cases, low-noise road surfaces are the most used mitigation action together with traffic flow reduction. Selecting the optimal surface is only the first problem that the public administration has to face. In the second place, it has to consider the issue of assessing the efficacy of the mitigation action. The purpose of the LEOPOLDO project was to improve the knowledge in the design and the characterization of low-noise road surfaces, producing guidelines helpful to the public administrations. Several experimental road surfaces were tested. Moreover, several measurement methods were implemented aiming to select those that are suitable for a correct assessment of the pavement performances laid as mitigation planning. In this paper, the experience gained in the LEOPOLDO project will be described, focusing on both the measurement methods adopted to assess the performance of a low-noise road surface and the criteria by which the experimental results have to be evaluated, presenting a comparison of the obtained results and their monitoring along time.