Railway noise in urban areas: assessment and prediction on infrastructure improvement combined with settlement development and regeneration in central Italy

It is well known that nowadays noise is one of the main causes of the disqualification of life: the tendency to reach the regulatory thresholds and the extension of noisy areas lead to increase the exposed population. Significant is the contribution of the railway and road sources. The railway infrastructure that crosses the territory straddling the municipalities of Campoleone and Aprilia, close to Rome, in central Italy, plays an important role in the national, social, and economic scenario. Its track, however, appears to conflict with the structure of the city, whose development is fragmented and strongly afflicted by unauthorized buildings; it constitutes a break in the urban environment and, together with the essential Pontina and Nettunense roads, it condemns the area to landscape and social degradation, subjecting the population that lives in the vicinity to various problems, including noise pollution. This study aims to assess the sound levels generated by the aforementioned infrastructures when crossing an urbanized area, considering a possible optimization of the railway service and a parallel improvement of the settlement in view of its expansion. The solutions that could be adopted to mitigate noise pollution are then addressed. To this end, four scenarios have been developed and possible noise control alternatives have been simulated by using SoundPLAN software: the burial of a railway section nearby the railway station, the management of the new buildings in terms of geometry and destinations, and a more traditional construction of acoustic barriers (Leq reduction = 3 ÷ 13 dB(A)). For the best, urbanistic and technical, solution an economic analysis was carried out.