As part of the update of Lisbon's strategic noise map, with 2022 as the reference year, it was found that all of the city's roads affect 74,118 people residing in the municipality, who are exposed to ambient noise levels above 65 decibels, associated with global annoyance - dB(A) -, depending on the noise indicator for the day, evening and night (Lden), that is, for the 24-hour period of the day.

These 74,118 people represent around 13.6% of the population residing in Lisbon, out of a total of 545,761 inhabitants, according to the 2021 Census.

Based on the regulations of the Lisbon Municipal Master Plan in force, the entire municipal territory is classified as a mixed zone, “and the population should not be exposed to external ambient noise levels higher than those defined in the General Noise Regulation, at 65 dB (A) and 55 dB(A) respectively for the Lden and Ln indicators [noise indicator for the night, from 23:00 to 07:00]”.

The documents relating to the update of Lisbon's strategic noise map were approved by the city council on Wednesday, in a private meeting, following a proposal from the PSD/CDS-PP leadership, to be submitted to the municipal assembly.

According to the strategic noise map, with data from 2022, “road traffic in the city of Lisbon continues to be the main cause of external ambient noise, both during the day-dusk-night period [Lden] and at night [Ln]”.

The document says that the distribution of ambient noise levels in Lisbon is directly related to the main road traffic routes.

In the case of road noise, “the influence of GIT [large transport infrastructures] on the resident population exposed to ambient noise levels above 65 dB(a) is much smaller”, according to the Lden indicator, which found 8,291 people affected. (1.5% of the resident population), when compared with the population affected by all highways, totalling 74,118 people (13.6%).

Other sources of noise included in the document are railway transport infrastructures, with data from 2007 on the Northern lines (from Santa Apolónia and Alcântara-Terra), Sintra (from Rossio and Gare do Oriente), Cintura (from Roma-Areeiro) and Cascais (from Cais do Sodré); Humberto Delgado Airport, with data from 2021; the Carris tram network and nightlife areas in the city, specifically in Doca de Santo Amaro, Bairro Alto, Santos, Cais do Sodré and Bica, with data from 2022.