Noise low-emission zones in Monza, Italy

© LIFE MONZA (undated), ‘Documents’ (http://www.lifemonza.eu/?q=en/node/41), accessed 8 August 2022.

Context

No harmonised definition of a low-emission zone (LEZ) has been established at the European level. Furthermore, LEZ requirements primarily focus on air quality and often include no reference to noise. One of the objectives of the LIFE MONZA — ‘methodologies for noise low emission zones introduction and management’ — project was therefore to establish a reproducible method for the introduction and management of LEZs for noise.

The Libertà district of Monza is characterised by street crossings and traffic lights at which vehicles, including heavy vehicles, are obliged to stop and start, creating problems related to noise exposure. Noise was also an issue at night because, although these vehicles stopped and started less frequently, they were travelling at a higher speed. People were exposed to very high levels of noise within a 30-metre range of the busy Viale Libertà, particularly people living in residences along the street and people working and studying at the local school. The district was therefore highlighted as a critical area in the noise action plan created in accordance with the Environmental Noise Directive. The project also aimed to reduce emissions of air pollutants from road traffic.

In both winter and spring, a noise-monitoring campaign was carried out before and after implementation of the measures. The measures assessed as part of the noise LEZ were largely broken down into top-down and bottom-up measures. Top-down measures included infrastructural changes, such as replacing the road surface with a bituminous conglomerate and protecting pedestrian crossings, and road traffic management measures, such as restricting the passage of heavy vehicles. Bottom-up measures included community participation, such as educational and awareness-raising activities in local schools, and the use of a Pedibus scheme to encourage students and parents to walk to school.

The following was observed after the measures were implemented:

• Noise levels during the day (L_day) were reduced by about 2dB(A), and during the evening (L_evening) and night (L_night) by 5-6dB(A).
• Noise levels during the day-evening-night period (L_den) were reduced by 3.5dB(A) in receiver buildings and areas located up to 30m from Viale Libertà and by 1.8dB(A) in the designated LEZ.
• The percentage of people exposed to L_den values higher than 65dB(A) in the noise LEZ decreased from 9.6% to 6.7%, while the percentage of people exposed to L_night values higher than 55dB(A) decreased from 12.8% to 4.7%.
• The number of transits was reduced by about 17% in winter and about 30% in summer, while average daily traffic flow was reduced by about 5%.

As part of the monitoring exercise, semi-structured interviews were conducted with experts involved in implementing the project. Low-noise emission asphalt repaving was widely considered the most effective measure for noise reduction. It was noted that, when traffic is relatively fluid and consists of light vehicles only, as at night, noise reduction is greatest because the low-noise asphalt mainly has an effect on rolling noise. During the daytime, when traffic is not fluid because of traffic lights, the efficacy of the low-noise asphalt road surface is reduced. It was also noted that the protected pedestrian crossings improved social relationships and liveability in the neighbourhood.

Guidelines on how to implement ‘noise low-emission zones’ were published as part of the project.